WO2021015054A1 - Carbonaceous material, method for producing same, electrode active material for electrochemical device, electrode for electrochemical device, and electrochemical device - Google Patents

Carbonaceous material, method for producing same, electrode active material for electrochemical device, electrode for electrochemical device, and electrochemical device Download PDF

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WO2021015054A1
WO2021015054A1 PCT/JP2020/027355 JP2020027355W WO2021015054A1 WO 2021015054 A1 WO2021015054 A1 WO 2021015054A1 JP 2020027355 W JP2020027355 W JP 2020027355W WO 2021015054 A1 WO2021015054 A1 WO 2021015054A1
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carbonaceous material
electrochemical device
electrode
oxidizing gas
precursor
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PCT/JP2020/027355
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French (fr)
Japanese (ja)
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裕之 西浪
裕美加 西田
西村　修志
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株式会社クラレ
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Priority to JP2021533966A priority Critical patent/JPWO2021015054A1/ja
Priority to CN202080051999.6A priority patent/CN114174224A/en
Priority to EP20843536.2A priority patent/EP4001215A4/en
Priority to US17/627,825 priority patent/US20220278327A1/en
Priority to KR1020217038817A priority patent/KR20220035327A/en
Publication of WO2021015054A1 publication Critical patent/WO2021015054A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/30—Active carbon
    • C01B32/312—Preparation
    • C01B32/318—Preparation characterised by the starting materials
    • C01B32/324—Preparation characterised by the starting materials from waste materials, e.g. tyres or spent sulfite pulp liquor
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/30—Active carbon
    • C01B32/312—Preparation
    • C01B32/318—Preparation characterised by the starting materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/30—Active carbon
    • C01B32/312—Preparation
    • C01B32/336—Preparation characterised by gaseous activating agents
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/30—Active carbon
    • C01B32/312—Preparation
    • C01B32/342—Preparation characterised by non-gaseous activating agents
    • C01B32/348—Metallic compounds
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/30—Active carbon
    • C01B32/354—After-treatment
    • C01B32/378—Purification
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/14—Arrangements or processes for adjusting or protecting hybrid or EDL capacitors
    • H01G11/20—Reformation or processes for removal of impurities, e.g. scavenging
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/24—Electrodes characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • H01G11/44—Raw materials therefor, e.g. resins or coal
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
    • H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/002—Details
    • H01G4/005—Electrodes
    • H01G4/008—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/13—Energy storage using capacitors

Definitions

  • the present invention relates to a carbonaceous material, a method for producing the same, an electrode active material for an electrochemical device, an electrode for an electrochemical device, and an electrochemical device.
  • the electric double layer capacitor which is one of the electrochemical devices, uses the capacity (electric double layer capacity) obtained only by the adsorption and desorption of physical ions without a chemical reaction, so it outputs more than the battery. Excellent in characteristics and life characteristics.
  • a lithium ion capacitor which is one of the electrochemical devices, is attracting attention as a hybrid capacitor capable of increasing the energy density of an electric double layer capacitor.
  • auxiliary power sources and regenerative energy in electric vehicles (EV) and hybrid vehicles (HV). has been done.
  • Such automotive electrochemical devices not only have higher energy densities, but also have higher durability and capacitance under harsh usage conditions (eg, in harsh temperature environments) compared to consumer applications. Improvement is required.
  • Patent Documents 1 and 2 disclose that activated carbon before or after pulverization is heat-treated at a high temperature in order to increase the capacitance and suppress gas generation after durability.
  • Patent Document 3 describes that the amount of oxygen in the skeleton is controlled in addition to the amount of surface functional groups of the activated carbon by heat-treating the activated carbon at a high temperature for the purpose of further improving the durability.
  • Patent Document 4 describes an increase in the specific surface area obtained by alkali activation and an improvement in the capacitance and durability of the highly crystallized activated carbon.
  • activated carbon obtained by alkali activation as described in Patent Document 4 generally has a chemical content equal to or higher than the amount of carbon added at the time of activation, and a step of removing residual chemicals after alkali activation is required. Therefore, the manufacturing method becomes complicated. Further, as compared with the activated carbon obtained by steam activation, the amount of functional groups at the time of activation is increased, and the durability may be lowered.
  • the present invention has been made in view of the above circumstances, and it is possible to obtain an electrochemical device having a high initial capacitance, a high effect of suppressing the amount of gas generated during charging / discharging, and excellent durability. It is an object of the present invention to provide a carbonaceous material and a method for producing the same, an electrode active material for an electrochemical device made of the carbonaceous material, an electrode for an electrochemical device using the same, and an electrochemical device.
  • the present inventors have arrived at the present invention as a result of repeated detailed studies on carbonaceous materials and methods for producing the same in order to solve the above problems.
  • the present invention includes the following preferred embodiments.
  • the BET specific surface area is 1550 to 2500 m 2 / g
  • the oxygen content / hydrogen content value per specific surface area is 1.00 to 2.10 mg / m 2
  • the conductivity is measured by powder resistance at a load of 12 kN.
  • a method for producing a carbonaceous material wherein the conductivity measured by powder resistance measurement of a carbonaceous material precursor to be subjected to a heating step performed in a final oxidizing gas atmosphere at a load of 12 kN is 11 to 16 S / cm.
  • Electrode for an electrochemical device according to the above [7] Electrode for an electrochemical device containing an active material.
  • a carbonaceous material and a method for producing the same which can obtain an electrochemical device having a high initial capacitance, a high effect of suppressing the amount of gas generated during charging / discharging, and excellent durability. It is possible to provide an electrode active material for an electrochemical device made of the carbonaceous material, an electrode for an electrochemical device using the same, and an electrochemical device.
  • the carbonaceous substance before the temperature lowering treatment in the temperature lowering step is referred to as "carbonaceous material precursor", and the carbonaceous material precursor is subjected to the final heat treatment and the temperature lowering treatment is performed.
  • the carbonaceous material obtained by the above is called “carbonaceous material”.
  • the carbide of the carbon precursor as a raw material may be referred to as “carbide” to distinguish it from the carbonaceous substance (activated carbon) obtained by activating the carbonaceous substance, but the "carbon” in the present invention may be used.
  • the “quality material precursor” broadly includes carbonaceous substances before the temperature lowering treatment, such as carbides of carbon precursors as raw materials and carbonaceous substances (activated carbon) obtained by activating the carbides. ..
  • the BET specific surface area is 1550 to 2500 m 2 / g
  • the value of hydrogen content / oxygen content per specific surface area is 1.00 to 2.10 mg / m 2
  • the powder under a load of 12 kN is 10 to 15 S / cm.
  • BET specific surface area of the carbonaceous material of the present invention is 1550 m 2 / g or more, preferably 1600 m 2 / g or more, and not more than 2500 m 2 / g, not more than 2450m 2 / g It is preferably 2400 m 2 / g or less, more preferably 2400 m 2 / g or less.
  • the capacitance per unit area is constant. Therefore, if the BET specific surface area is less than 1550 m 2 / g, it is difficult to sufficiently increase the capacitance per unit mass.
  • the resistance that is thought to be due to the diffusion resistance of non-aqueous electrolyte ions in the pores tends to increase during charging and discharging under a large current.
  • the BET specific surface area exceeds 2500 m 2 / g, the bulk density of the electrode manufactured by using the carbonaceous material tends to be low, and the capacitance per volume tends to be low.
  • the carbonaceous material of the present invention has a value of oxygen content (mass%) / hydrogen content (mass%) per specific surface area (hereinafter, may be simply referred to as "O / H per specific surface area”) 1 and a .00mg / m 2 or more, preferably 1.10 mg / m 2 or more, more preferably 1.20 mg / m 2 or more, and at 2.10mg / m 2 or less, 2. preferably 08mg / m 2 or less, more preferably 2.06 mg / m 2 or less.
  • oxygen content, O indicates the mass of oxygen in the carbonaceous material obtained from the measurement results of elemental analysis described later, and the amount of surface oxygen existing on the surface of the carbonaceous material and the skeleton. Shows the sum of the amount of oxygen incorporated and present.
  • hydrogen content, H indicates the amount of hydrogen present on the outer periphery of the carbon crystal of the carbonaceous material.
  • the amount of surface oxygen present on the surface of the carbonaceous material represents the degree of functional groups that contribute to the deterioration of durability and gas generation, and the amount of oxygen present in the skeleton of the carbonaceous material.
  • the amount of hydrogen present on the outer periphery of the crystal represents the degree of development of the carbon crystal structure.
  • the O / H per specific surface area is an index for suppressing the growth of carbon crystals of the carbonaceous material and showing an appropriate amount of oxygen from the viewpoint of durability and gas generation. Therefore, when the O / H per specific surface area is equal to or higher than the above lower limit value, it is presumed that oxygen on the surface of the carbonaceous material is appropriately present and the affinity with the binder is improved, and the electrode moldability is excellent. .. In addition, it is presumed that the carbon structure of the carbonaceous material is sufficiently developed and the crystallinity is high, so that the electrical conductivity of the carbonaceous material itself is improved.
  • the O / H per specific surface area is not more than the above upper limit value, the amount of surface oxygen existing on the surface of the carbonaceous material is appropriately reduced, and gas generation during charging / discharging is suppressed. It is presumed. Further, it is presumed that the excessive development of the carbon crystal structure of the carbonaceous material can be suppressed, and the shrinkage of the pores of the carbonaceous material accompanying the suppression can be suppressed, and it is easy to suppress the decrease in the initial capacitance per mass.
  • the value of O / H per specific surface area in the present invention is a value calculated according to the method described in Examples described later.
  • the carbonaceous material of the present invention has a conductivity of 10 S / cm or more, preferably 10.5 S / cm or more, more preferably 11 or more, and 15 S, as measured by powder resistance at a load of 12 kN. It is / cm or less, preferably 14.5 S / cm or less, and more preferably 14 S / cm or less.
  • the conductivity measured by powder resistance measurement at a load of 12 kN is not more than the above upper limit value, excessive development of the carbon crystal structure of the carbonaceous material can be suppressed, and the accompanying shrinkage of pores of the carbonaceous material can be suppressed. Therefore, it is presumed that the decrease in the initial capacitance per mass is suppressed.
  • the average pore diameter of the carbonaceous material of the present invention is preferably 1.75 nm or more, more preferably 1.78 nm or more, still more preferably 1.80 nm or more.
  • the average pore diameter of the carbonaceous material of the present invention is preferably 2.60 nm or less, more preferably 2.55 nm or less, still more preferably 2.50 nm or less.
  • the average pore diameter is not more than the above upper limit value, the bulk density of the electrode manufactured by using the carbonaceous material tends to be high, and the capacitance per volume tends to be high.
  • the BET specific surface area and the average pore diameter of the carbonaceous material within the above upper and lower limit values, respectively, an electrochemical device having a high capacitance per unit mass and volume and a low resistance can be obtained. A more suitable carbonaceous material can be obtained.
  • the average pore diameter can be measured by the method described in Examples described later.
  • the total pore volume of the carbonaceous material of the present invention is preferably 0.70 cm 3 / g or more, and more preferably 0.72 cm 3 / g or more.
  • the total pore volume of the carbonaceous material of the present invention is preferably 1.30 cm 3 / g or less, more preferably 1.29 cm 3 / g or less, and further preferably 1.28 cm 3 / g or less. Is.
  • the total pore volume is not more than the above upper limit value, the bulk density of the electrode manufactured by using the carbonaceous material tends to be high, and the capacitance per volume tends to be high.
  • the total pore volume can be measured by the method described in Examples described later.
  • the carbonaceous material of the present invention preferably has an oxygen content (% by mass) / hydrogen content (mass%) of 2.0 or more, more preferably 2.25 or more, and 2.5 or more. It is more preferably 2.6 or more, particularly preferably 2.7 or more, more preferably 4.3 or less, and more preferably 4.2 or less. It is preferable, and it is more preferably 4.1 or less. Within the above range, the effect of suppressing the generation of gas and the effect of suppressing the decrease in capacitance can be further enhanced.
  • the average particle size of the carbonaceous material of the present invention is preferably 30 ⁇ m or less, more preferably 20 ⁇ m or less, preferably 2 ⁇ m or more, and more preferably 4 ⁇ m or more. When it is within the above range, the electrode manufactured by using the carbonaceous material can be thinned, the bulk density is improved, and the capacitance per volume tends to be high.
  • the value of the average particle size in the present invention is a value calculated according to the method described in Examples described later.
  • the carbonaceous material of the present invention is, for example, A heating step in which the carbonaceous material precursor is heated to 330 ° C. or higher in an oxidizing gas atmosphere, and a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere is cooled in a non-oxidizing gas atmosphere. Including the temperature lowering process When the heating step performed in the oxidizing gas atmosphere is included once, the temperature lowering step is carried out following the heating step. When the heating step performed in the oxidizing gas atmosphere is included a plurality of times, at least the heating step performed in the final oxidizing gas atmosphere is followed by the temperature lowering step.
  • the conductivity of the carbonaceous material precursor subjected to the heating step carried out in the final oxidizing gas atmosphere by measuring the powder resistance at a load of 12 kN is 11 to 16 S / cm. It can be manufactured by the method.
  • the temperature lowering step is carried out following the heating step, and the heating step carried out in the oxidizing gas atmosphere is included a plurality of times. If so, the temperature lowering step is carried out at least following the heating step carried out in the final oxidizing gas atmosphere.
  • the pores are formed by cooling the carbonaceous material precursor in a non-oxidizing gas atmosphere following the final heating step of heating the carbonic material precursor to 330 ° C. or higher in an oxidizing gas atmosphere. It is possible to reduce the amount of surface oxygen and the amount of oxygen in the skeleton present on the surface of the obtained carbonaceous material while suppressing shrinkage.
  • the heating step carried out in an oxidizing gas atmosphere is carried out, for example, after an activation step of activating carbides of a carbon precursor as a raw material or an acid cleaning step of removing impurities if necessary.
  • Examples include a deoxidizing step.
  • the activation step may be carried out in one step or divided into two or more steps in order to obtain the desired specific surface area.
  • the acid cleaning for removing impurities in the substance may be carried out after the activation is completed, may be carried out during the multi-step activation, or may be carried out repeatedly several times. After the acid cleaning, it is preferable to perform a heat treatment (deoxidation step) in order to remove an acid component remaining in the pores, for example, chlorine.
  • the carbonaceous material precursor in the step of heating the carbonaceous material precursor to 330 ° C. or higher in an oxidizing gas atmosphere, in the temperature lowering process after the final heating step is completed, the carbonaceous material precursor is heated in a non-oxidizing gas atmosphere. It is important to cool.
  • the heating step performed in an oxidizing gas atmosphere is performed a plurality of times, the temperature lowering (cooling) other than the temperature lowering step of the carbonaceous material precursor heated to 330 ° C. or higher by the final heating step is not performed. It may be carried out in an oxidizing atmosphere, or may be carried out in an oxidizing gas atmosphere.
  • the temperature of the carbonaceous material precursor heated to 330 ° C. or higher by the heating step carried out in the final oxidizing gas atmosphere is lowered in a non-oxidizing gas atmosphere.
  • heating in a non-oxidizing gas atmosphere may be included as long as it does not affect the effect of the present invention.
  • the final heating step of the steps of heating the carbonaceous material precursor contained in the production method of the present invention to 330 ° C. or higher is under an oxidizing gas atmosphere. It is preferable that the temperature lowering process is carried out in a non-oxidizing gas atmosphere.
  • the conductivity of the carbonaceous material precursor subjected to the heating step carried out in the final oxidizing gas atmosphere by measuring the powder resistance at a load of 12 kN is preferably 11 to 16 S / cm. is there.
  • the conductivity of the carbonaceous material precursor measured by powder resistance at a load of 12 kN is 11 to 16 S / cm at the stage of being subjected to the heat treatment carried out in the final oxidizing gas atmosphere, the carbonaceous material precursor A carbonaceous material having a high degree of crystallization is obtained, and when used as a material for an electrode active material for an electrochemical device, a high capacity retention rate is likely to be exhibited and durability is likely to be improved.
  • the initial capacitance is high, the gas generation suppression effect during charging and discharging is excellent, and due to the highly developed crystallized structure, electricity with excellent durability that can maintain a high initial capacitance for a long period of time. It is possible to obtain a carbonaceous material capable of producing a chemical device.
  • the heating step carried out in an oxidizing gas atmosphere is included only once, the heating step is carried out in the above-mentioned "final oxidizing gas atmosphere". It becomes a heating process.
  • each step will be described in detail.
  • the carbon precursor used as a raw material for the carbonaceous material is not particularly limited as long as it forms the carbonaceous material by activation, and is a plant-derived carbon precursor, a mineral-derived carbon precursor, or a natural material. It can be widely selected from a carbon precursor derived from a material and a carbon precursor derived from a synthetic material. From the viewpoint of reducing harmful impurities, protecting the environment and from a commercial point of view, the carbonaceous material of the present invention is preferably based on a carbon precursor derived from a plant, in other words, the carbonaceous material of the present invention. It is preferable that the carbon precursor used as a material is derived from a plant.
  • Examples of mineral-derived carbon precursors include petroleum-based and carbon-based pitches and coke.
  • Examples of carbon precursors derived from natural materials include natural fibers such as cotton and hemp, regenerated fibers such as rayon and viscose rayon, and semi-synthetic fibers such as acetate and triacetate.
  • Examples of carbon precursors derived from synthetic materials include polyamide-based resins such as nylon, polyvinyl alcohol-based resins such as vinylon, polyacrylonitrile-based resins such as acrylic, polyolifin-based resins such as polyethylene and polypropylene, polyurethane, phenol-based resins, and vinyl chloride-based resins. Can be mentioned.
  • the plant-derived carbon precursor is not particularly limited, and examples thereof include palm husks, coffee beans, tea leaves, sugar cane, fruits (for example, mandarin oranges and bananas), straw, rice husks, hardwoods, conifers, and bamboo.
  • This example includes waste after use for its intended purpose (eg, used tea leaves), or some plant material (eg, banana or tangerine peel).
  • These plant raw materials may be used alone or in combination of two or more.
  • coconut shells are preferable because they are easily available and carbonaceous materials having various properties can be produced. Therefore, the carbonaceous material of the present specification is preferably based on a plant-derived carbon precursor, and more preferably based on a coconut shell-derived carbon precursor.
  • the coconut shell is not particularly limited, and examples thereof include coconut husks such as palm palm (oil palm), coconut palm, salak, and lodoicea. These coconut shells may be used alone or in combination of two or more. Palm husks of coconut and palm palm, which are biomass wastes generated in large quantities after using coconut as a raw material for foods, detergents, biodiesel oil, etc., are particularly preferable from the viewpoint of availability.
  • the method for obtaining the carbide, which is a carbonaceous material precursor, from the carbon precursor is not particularly limited, and can be produced by using a method known in the art.
  • the carbon precursor used as a raw material may be an inert gas such as nitrogen, carbon dioxide, helium, argon, carbon monoxide or fuel exhaust gas, a mixed gas of these inert gases, or a main component of these inert gases. It can be produced by firing (carbon dioxide treatment) at a temperature of about 400 to 800 ° C. in an atmosphere of a mixed gas with the above gas.
  • a known method such as a fixed floor method, a moving floor method, a fluidized bed method, a multi-stage floor method, or a rotary kiln can be adopted.
  • the carbonaceous material precursor (activated carbon) as a raw material can be obtained, for example, by activating the above-mentioned carbide.
  • the activation treatment is a treatment of forming pores on the surface of a carbide and converting it into a porous carbonaceous substance, thereby obtaining a carbonaceous substance (carbonaceous material precursor) having a large specific surface area and pore volume. Can be done.
  • the carbide is used as it is without the activation treatment, the specific surface area and pore volume of the obtained carbonaceous substance are not sufficient, and the development of the carbon crystal structure is also insufficient. Therefore, when it is used as an electrode material.
  • the activation treatment usually requires heating of carbides, and the obtained carbonaceous material precursor is heated to 330 ° C. or higher in association with the activation step. Therefore, the activation step can be one aspect of the heating step in the present invention.
  • the activation treatment can be carried out by a method general in the art, and there are mainly two types of treatment methods, a gas activation treatment and a chemical activation treatment.
  • a method of heating carbides in the presence of water vapor, carbon dioxide, air, oxygen, combustion gas, or a mixed gas thereof is known.
  • an activator such as zinc chloride, calcium chloride, phosphoric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide is used as a carbon precursor or a carbide of the carbon precursor.
  • a method of mixing with and heating in an inert gas atmosphere is known.
  • the drug activation requires a step of removing the residual drug, the production method becomes complicated, and the amount of functional groups at the time of activation increases, so that the gas activation treatment is preferable.
  • the partial pressure is preferably in the range of 10 to 60%.
  • the partial pressure of water vapor is 10% or more, the activation is likely to proceed sufficiently, and when it is 60% or less, the rapid activation reaction is suppressed and the reaction is easy to control.
  • the total amount of the activating gas supplied in the steam activation is preferably 50 to 10000 parts by mass, more preferably 100 to 5000 parts by mass, and 200 to 3000 parts by mass with respect to 100 parts by mass of the carbide. Is even more preferable.
  • the total amount of the activated gas to be supplied is within the above range, the activation reaction can proceed more efficiently.
  • the specific surface area and pore volume of the carbonaceous material can be controlled by changing the method of activating the carbide and its conditions.
  • a carbonaceous material precursor when a carbonaceous material precursor is obtained by steam activation treatment, it can be controlled by the gas type used, the concentration, the heating temperature, the reaction time, and the like.
  • the heating temperature (activation temperature) thereof when a carbonaceous material precursor is obtained by steam activation treatment, is usually 700 to 1100 ° C., preferably 800 to 1000 ° C., although it depends on the type of gas used. It is preferably 850 to 1000 ° C.
  • the "reaction rate at the time of activation” means the amount of increase in the BET specific surface area per minute.
  • the reaction rate at the time of activation is preferably 3.5 m 2 / g or less per minute at a temperature of, for example, 850 to 1000 ° C. , 3.0 m 2 / g or less, more preferably 0.5 m 2 / g or more, and more preferably 0.75 m 2 / g or more.
  • the reaction rate at each step may be appropriately determined in consideration of manufacturing equipment, productivity, etc., but the reaction rate is within the above range at least in a part. It is easy to control the carbon crystal structure of the obtained carbonaceous material precursor.
  • the reaction rate at the time of activation is, for example, the contact conditions (contact efficiency, activation gas type, activation gas amount and activation gas concentration / supply amount, etc.) between the carbide to be activated and the activation gas, the activation temperature, and the reaction auxiliary substance. It can be controlled by adjusting the type, amount, and its state (dispersion state and salt composition).
  • the contact conditions between the carbide and the activation gas can be controlled by the activation method, the equipment / equipment used for activation, the amount of supplied gas, the concentration, and the like. In the present invention, it is preferable to adopt the activation method that can achieve the reaction rate at the time of activation.
  • the frequency of contact of the activation gas with carbides is high, so that the decarburization reaction is easy to proceed, whereas a rotary kiln is used.
  • the rotary kiln is suitable as the equipment / equipment used for activation.
  • the activation treatment is performed so that the conductivity of the carbonaceous material precursor obtained by the activation step is 11 to 16 S / cm by measuring the powder resistance at a load of 12 kN. Is preferable.
  • a carbonaceous material may be produced using activated carbon that has already been activated as a starting material. Even in this case, it is preferable that the activated carbon (carbonaceous material precursor) as a starting material has a high powder conductivity, and the conductivity measured by powder resistance measurement at a load of 12 kN is 11 to 16 S / cm. Is more preferable.
  • the method for producing a carbonaceous material may include an acid cleaning step.
  • the acid cleaning step is a step for removing impurities such as metal components contained in the carbonaceous material precursor by cleaning the carbonaceous material precursor with a cleaning liquid containing an acid.
  • the acid cleaning step can be performed by immersing the carbonaceous material precursor obtained after activation in a cleaning solution containing an acid.
  • the cleaning liquid include mineral acids and organic acids.
  • the mineral acid include hydrochloric acid, sulfuric acid and the like.
  • the organic acid examples include saturated carboxylic acids such as formic acid, acetic acid, propionic acid, oxalic acid and tartaric acid, and citric acid, and aromatic carboxylic acids such as benzoic acid and terephthalic acid.
  • the acid used in the cleaning liquid is preferably a mineral acid, more preferably hydrochloric acid, from the viewpoint of detergency. It is preferable to perform washing with an acid and then further wash with water or the like to remove excess acid. By this operation, the load on the equipment in the subsequent process can be reduced.
  • the acid washing step may be carried out after the primary activation step or after the multi-step activation step.
  • the cleaning solution can usually be prepared by mixing an acid and an aqueous solution.
  • the aqueous solution include water and a mixture of water and a water-soluble organic solvent.
  • the water-soluble organic solvent include alcohols such as methanol, ethanol, propylene glycol and ethylene glycol.
  • the concentration of the acid in the cleaning solution is not particularly limited, and the concentration may be appropriately adjusted according to the type of acid used.
  • the acid concentration of the cleaning liquid is preferably 0.1 to 3.0%, more preferably 0.3 to 1.0%, based on the total amount of the cleaning liquid. If the hydrochloric acid concentration is too low, it is necessary to increase the number of picklings in order to remove impurities, and conversely, if the hydrochloric acid concentration is too high, the amount of residual hydrochloric acid increases. The process can be performed, which is preferable from the viewpoint of productivity.
  • the pH of the cleaning solution is not particularly limited, and may be appropriately adjusted according to the type of acid used, the object to be removed, and the like.
  • the liquid temperature for pickling or washing with water is not particularly limited, but is preferably 0 to 98 ° C, more preferably 10 to 95 ° C, and further preferably 15 to 90 ° C. preferable.
  • the temperature of the cleaning liquid when immersing the carbonaceous material precursor is within the above range, it is desirable that cleaning can be performed in a practical time and while suppressing the load on the apparatus.
  • the mass ratio of the cleaning liquid and the carbonic material precursor may be appropriately adjusted according to the type, concentration, temperature, etc. of the cleaning liquid to be used.
  • the mass of the carbonaceous material precursor to be immersed is usually 0.1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 1.5 to 10% by mass with respect to the mass of the cleaning liquid. preferable.
  • impurities eluted in the cleaning liquid are less likely to precipitate from the cleaning liquid, reattachment to the carbonaceous material precursor is likely to be suppressed, and volumetric efficiency becomes appropriate, which is desirable from the viewpoint of economy.
  • the atmosphere for cleaning is not particularly limited, and may be appropriately selected depending on the method used for cleaning.
  • cleaning is usually carried out in an air atmosphere.
  • the cleaning may be performed once or multiple times with one type of cleaning liquid, or may be performed a plurality of times in combination of two or more types of cleaning liquids.
  • the method for cleaning the carbonaceous material precursor is not particularly limited as long as the carbonaceous material precursor can be immersed in the cleaning liquid, and the cleaning liquid is continuously added, retained for a predetermined time, and immersed while being withdrawn.
  • the method may also be a method in which the carbonaceous material precursor is immersed in a cleaning solution, allowed to stay for a predetermined time, deliquesed, and then a new cleaning solution is added to repeat dipping and deliquescing. Further, it may be a method of renewing the entire cleaning liquid or a method of renewing a part of the cleaning liquid.
  • the time for immersing the carbonaceous material precursor in the cleaning liquid can be appropriately adjusted according to the acid used, the concentration of the acid, the treatment temperature, and the like.
  • the method for producing a carbonaceous material may include a deoxidizing step for removing an acid (for example, hydrochloric acid or the like) derived from an acid cleaning solution remaining after acid cleaning.
  • the deoxidizing step can be carried out by heating the carbonaceous material precursor in an oxidizing gas atmosphere after acid cleaning. Since the carbonaceous material precursor is usually heated to 330 ° C. or higher in the deoxidizing step, the deoxidizing step can be one aspect of the heating step in the present invention. In addition, it is possible to adjust the contact time and temperature with the oxidizing gas to remove the residual acid with further activation reaction.
  • the conductivity measured by powder resistance measurement of the carbonaceous material precursor at a load of 12 kN at the stage of being subjected to the heating step is 11 to 11. It is preferably 16 S / cm.
  • the powder conductivity of the carbonaceous material precursor changes by subjecting it to a heat treatment of 330 ° C. or higher, and does not change significantly unless such a heat treatment is performed.
  • the body conductivity may be measured in consideration of each step included in the manufacturing method to be adopted, and does not necessarily have to be immediately before the final heating step in the oxidizing gas atmosphere.
  • the heating step performed before the deoxidizing step ( That is, in this case, the measurement may be performed from after the activation step) to immediately before the deoxidization step.
  • the gas used in the gas activation step can be used.
  • "under an oxidizing gas atmosphere” means a state in which the total amount of oxidizing gas per carbonaceous material precursor in the container is 1.5 L / kg or more.
  • the treatment temperature is preferably 500 to 1000 ° C, more preferably 650 to 850 ° C. It is preferable that the temperature is within the above temperature range because deoxidation can be performed without significantly changing the pore structure of the carbonaceous material precursor.
  • the time varies depending on the temperature, but is usually about 30 minutes to 3 hours.
  • the deoxidizing method is not particularly limited, and for example, a known method such as a fixed floor method, a moving floor method, a fluidized bed method, a multi-stage floor method, or a rotary kiln can be adopted.
  • the average particle size of the carbon precursor or the carbonaceous material precursor derived from coconut husk used in the activation step or the deoxidization step can be adjusted according to the activation and deoxidation steps.
  • the method for producing a carbonaceous material of the present invention includes a temperature lowering step of lowering the temperature of a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere in a non-oxidizing gas atmosphere. That is, a step of heating the carbonaceous material precursor to 330 ° C. or higher in an oxidizing gas atmosphere in order to suppress the formation of functional groups due to the reaction between the oxidizing gas (for example, oxygen) existing in the environment at the time of temperature decrease and the carbon surface.
  • a step of lowering the temperature after the final heating step is performed in a non-oxidizing gas atmosphere is included. Thereby, the carbonaceous material of the present invention can be obtained.
  • a method of heating a carbonaceous material precursor in an inert gas atmosphere in order to remove acidic functional groups present on the surface of the carbonaceous material precursor after an activation treatment or a deoxidation step is known.
  • pore shrinkage is likely to occur due to heating, and it may be difficult to secure a sufficiently high initial capacitance when used in an electrochemical device.
  • problems in terms of productivity such as the need for further steps for heating and the need to strictly control the heating conditions.
  • pore shrinkage occurs. It is possible to obtain a carbonaceous material capable of producing an electrochemical device having a high initial capacitance.
  • the temperature of the carbonaceous material precursor heat-treated in the final oxidizing gas atmosphere is lowered to preferably 200 ° C. or lower, more preferably 150 ° C. or lower in a non-oxidizing gas atmosphere.
  • the temperature lowering time to the above temperature depends on the amount of oxidizing gas existing in the temperature lowering environment, but it is preferably within 3 hours, preferably within 1 hour in consideration of productivity. Further, it is more desirable from the viewpoint of oxidation suppression and productivity to use an indirect cooling device (for example, a cooling kiln) to increase the temperature lowering rate and shorten the time in the temperature region where the carbonaceous material precursor can be oxidized.
  • an indirect cooling device for example, a cooling kiln
  • non-oxidizing gas examples include nitrogen gas, dry hydrogen gas, ammonia gas, argon gas, helium gas, hydrogen gas, carbon monoxide gas, and hydrocarbon gas. Only one kind of these gases may be used alone, or two or more kinds of these gases may be used as a mixed gas.
  • the non-oxidizing gas atmosphere means an atmosphere in which the oxidizing gas is significantly reduced as compared with an atmosphere containing a large amount of oxidizing gas such as air.
  • "under a non-oxidizing gas atmosphere” means a state in which the total amount of oxidizing gas per carbonaceous material precursor in the container is 0.7 L / kg or less.
  • the total amount of oxidizing gas present in the environment at the time of lowering temperature is preferably 0.5 L / Kg or less, and preferably 0.1 L / Kg or less per carbonaceous material precursor. More preferred. Within the above range, the formation of functional groups due to the reaction between the oxidizing gas and the carbon surface in the temperature lowering process can be suppressed.
  • the method for producing a carbonaceous material may include a pulverization step.
  • the pulverization step is a step for controlling the shape and particle size of the finally obtained carbonaceous material to a desired shape and particle size. Due to its characteristics, the carbonaceous material of the present invention is particularly suitable as a material for a non-aqueous polar electrode used in an electrochemical device or the like, and the average particle size is preferably 4 to 15 ⁇ m as a particle size suitable for such applications. , More preferably, the carbonaceous material is ground to a size of 5 to 10 ⁇ m.
  • the crusher used for crushing is not particularly limited, and for example, a known crusher such as a cone crusher, a double roll crusher, a disc crusher, a rotary crusher, a ball mill, a centrifugal roll mill, a ring roll mill, a centrifugal ball mill, or a jet mill can be used. , Can be used alone or in combination.
  • the method for producing a carbonaceous material may include a classification step.
  • a classification step For example, it is possible to obtain carbonaceous material particles having a narrow particle size distribution width by excluding particles having a particle diameter of 1 ⁇ m or less. By removing such fine particles, it is possible to reduce the amount of binder in the electrode configuration.
  • the classification method is not particularly limited, and examples thereof include classification using a sieve, wet classification, and dry classification.
  • the wet classifier include classifiers that utilize principles such as gravity classification, inertial classification, hydraulic classification, and centrifugal classification.
  • the dry classifier include classifiers that utilize principles such as sedimentation classification, mechanical classification, and centrifugal classification. From the viewpoint of economy, it is preferable to use a dry classification device.
  • crushing and classification can be carried out using one device.
  • pulverization and classification can be carried out using a jet mill having a dry classification function.
  • a device in which the crusher and the classifier are independent can be used. In this case, crushing and classification can be performed continuously, but crushing and classification can also be performed discontinuously.
  • the carbonaceous material of the present invention can be suitably used as an electrode material or the like for various electrochemical devices. Therefore, in one embodiment of the present invention, the electrode active material for an electrochemical device and a method for producing the electrode active material can be provided by using the carbonaceous material of the present invention, and the electrode active material or the electrode active material can be provided.
  • An electrode for an electrochemical device and a method for manufacturing the same can be provided by using the electrode active material obtained by the manufacturing method of the above, and further, the electrode or the electrode obtained by the manufacturing method of the electrode is used for the electrochemical device and the method thereof.
  • a manufacturing method can be provided.
  • the electrode active material for an electrochemical device can be produced by using the carbonaceous material of the present invention.
  • the manufacturing process includes, for example, an electrode material such as a step of kneading a carbonaceous material of the present invention as a raw material with components such as a conductivity-imparting agent, a binder, and a solvent, and a step of coating and drying the kneaded product.
  • a manufacturing process generally used in the art can be included.
  • the electrode for an electrochemical device can be manufactured by using the electrode active material, and the manufacturing process thereof includes, for example, a step of adding a solvent to the electrode active material as a raw material to prepare a paste, and the paste. Can be included in a step of drying and removing the solvent after applying the above to a current collector plate such as an aluminum foil, and a step of putting the paste in a mold and press-molding.
  • the conductivity-imparting agent used for this electrode for example, acetylene black, ketjen black and the like can be used.
  • the binder for example, a fluorine-based polymer compound such as polytetrafluoroethylene or polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubber, petroleum pitch, phenol resin and the like can be used.
  • the solvent include water, alcohols such as methanol and ethanol, saturated hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene, xylene and mesityrene, ketones such as acetone and ethylmethylketone, and acetic acid.
  • Esters such as methyl and ethyl acetate, amides such as N, N-dimethylformamide and N, N-diethylformamide, cyclic amides such as N-methylpyrrolidone and N-ethylpyrrolidone and the like can be used.
  • an electrochemical device can be manufactured by using the electrode.
  • an electrochemical device has an electrode, an electrolytic solution, and a separator as a main configuration, and has a structure in which a separator is arranged between a pair of electrodes.
  • the electrolytic solution include an electrolytic solution in which an amidine salt is dissolved in an organic solvent such as propylene carbonate, ethylene carbonate, methyl ethyl carbonate, and acetonitrile, an electrolytic solution in which a quaternary ammonium salt of perchloric acid is dissolved, and quaternary ammonium and lithium.
  • Examples thereof include an electrolytic solution in which a boron tetrafluoride salt and a phosphorus hexafluoride salt of an alkali metal are dissolved, and an electrolytic solution in which a quaternary phosphonium salt is dissolved.
  • the separator include non-woven fabrics, cloths, and micropore films containing cellulose, glass fibers, or polyolefins such as polyethylene and polypropylene as main components. Electrochemical devices can be manufactured, for example, by arranging these major configurations in a manner conventionally common in the art.
  • the electrochemical device manufactured using the carbonaceous material of the present invention has high electrical conductivity and is a carbonaceous material without performing heat treatment accompanied by a decrease in the specific surface area and pore shrinkage of the carbonaceous material. Since the amount of surface functional groups and oxygen in the skeleton present on the surface is reduced, the initial capacitance can be increased, the reactivity with the electrolytic solution is low, and the effect of suppressing gas generation during charging and discharging is achieved. It is high, can suppress the decrease in capacitance due to long-term use, has excellent durability, and can maintain excellent performance even at low temperatures.
  • Average pore diameter (nm) total pore volume (cm 3 / g) / specific surface area (m 2 / g) x 4000
  • the particle size of the carbonaceous material was measured by a laser diffraction measurement method. That is, the carbonaceous material to be measured was put into ion-exchanged water together with a surfactant, and ultrasonic vibration was applied using BRANSONIC M2800-J manufactured by EMERSON to prepare a uniform dispersion liquid, and Microtrac manufactured by Microtrack, USA. It was measured by the absorption method using MT3000. Further, as the surfactant used for the purpose of uniform dispersion, "Triton-X 100" manufactured by Kao Corporation was used. The surfactant was added in an appropriate amount which can be uniformly dispersed and does not generate bubbles or the like which affect the measurement.
  • Example 1 Reaction rate when activating at 950 ° C using propane combustion gas and steam (partial pressure of steam: 18%) with char (BET specific surface area: 370 m 2 / g) made from coconut husks produced in the Philippines.
  • the primary activation was carried out at 1.4 m 2 / g per minute until the following specific surface area was obtained, to obtain a primary activated granular carbonaceous material precursor having a BET specific surface area of 1902 m 2 / g and an average pore diameter of 1.93 nm.
  • the total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (1) having a BET specific surface area of 1919 m 2 / g and an average pore diameter of 1.93 nm.
  • Various physical properties of the carbonaceous material (1) were measured. The results are shown in Table 1.
  • the mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (2) having a BET specific surface area of 1871 m 2 / g and an average pore diameter of 2.00 nm.
  • Various physical properties of the carbonaceous material (2) were measured. The results are shown in Table 1.
  • the primary activation was carried out at 1.2 m 2 / g per minute until the following specific surface area was obtained, to obtain a primary activated granular carbonaceous material precursor having a BET specific surface area of 1924 m 2 / g and an average pore diameter of 1.93 nm.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (4) having a BET specific surface area of 1782 m 2 / g and an average pore diameter of 1.96 nm.
  • Various physical properties of the carbonaceous material (4) were measured. The results are shown in Table 1.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (5) having a BET specific surface area of 1698 m 2 / g and an average pore diameter of 1.97 nm.
  • Various physical properties of the carbonaceous material (5) were measured. The results are shown in Table 1.
  • Example 2 In the same manner as in Example 1, a primary activated granular carbonaceous material precursor having a BET specific surface area of 1688 m 2 / g and an average pore diameter of 1.81 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C.
  • hydrochloric acid concentration: 0.5 specification, diluent: ion-exchanged water
  • nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container).
  • the total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (6) having a BET specific surface area of 1701 m 2 / g and an average pore diameter of 1.81 nm.
  • Various physical properties of the carbonaceous material (6) were measured. The results are shown in Table 1.
  • Example 3 In the same manner as in Example 1, a primary activated granular carbonaceous material precursor having a BET specific surface area of 2372 m 2 / g and an average pore diameter of 2.25 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C.
  • hydrochloric acid concentration: 0.5 specification, diluent: ion-exchanged water
  • nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container).
  • the total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (7) having a BET specific surface area of 2382 m 2 / g and an average pore diameter of 2.25 nm.
  • Various physical properties of the carbonaceous material (7) were measured. The results are shown in Table 1.
  • a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, the gas is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the secondary activated granular carbonaceous material precursor in the container is 1.5 L / L.
  • the mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (8) having a BET specific surface area of 1615 m 2 / g and an average pore diameter of 2.04 nm.
  • Various physical properties of the carbonaceous material (8) were measured. The results are shown in Table 1.
  • a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C.
  • nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container).
  • the total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (9) having a BET specific surface area of 1615 m 2 / g and an average pore diameter of 2.01 nm.
  • Various physical properties of the carbonaceous material (9) were measured. The results are shown in Table 1.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (10) having a BET specific surface area of 1486 m 2 / g and an average pore diameter of 2.02 nm.
  • Various physical properties of the carbonaceous material (10) were measured. The results are shown in Table 1.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (11) having a BET specific surface area of 1448 m 2 / g and an average pore diameter of 2.03 nm.
  • Various physical properties of the carbonaceous material (11) were measured. The results are shown in Table 1.
  • a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, the gas is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the secondary activated granular carbonaceous material precursor in the container is 1.5 L / L.
  • the mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
  • This carbonaceous material was finely pulverized so that the average particle size was 6 ⁇ m to obtain a carbonaceous material (12) having a BET specific surface area of 2243 m 2 / g and an average pore diameter of 2.23 nm.
  • Various physical properties of the carbonaceous material (12) were measured. The results are shown in Table 1.
  • Electrode cell fabrication Using the carbonaceous materials prepared in Examples 1 to 3 and Comparative Examples 1 to 9, an electrode composition was obtained according to the following electrode preparation method, and a polarizable electrode was prepared using the electrode composition. Further, a measuring electrode cell (electrochemical device) was prepared using the polarizable electrode. Using the obtained measurement electrode cell, capacitance measurement, durability test and gas generation amount measurement were performed according to the following methods. The measurement results are shown in Table 2.
  • the carbonaceous materials, conductive auxiliary materials and binders prepared in Examples 1 to 3 and Comparative Examples 1 to 9 were decompressed in advance at 120 ° C. in an atmosphere of reduced pressure (0.1 KPa or less) for 16 hours or more. It was dried and used.
  • the carbonaceous material, the conductive auxiliary material and the binder are weighed so that the ratio of (mass of carbonaceous material): (mass of conductive auxiliary material): (mass of binder) is 81: 9: 10 and kneaded. did.
  • the conductive auxiliary material conductive carbon black "Denka Black Granule" manufactured by Denki Kagaku Kogyo Co., Ltd.
  • the etched aluminum foil 3 manufactured by Hosen Co., Ltd. was coated with the conductive adhesive 2 "HITASOL GA-715" manufactured by Hitachi Kasei Kogyo Co., Ltd. so that the coating thickness was 100 ⁇ m. Then, as shown in FIG. 3, the etched aluminum foil 3 coated with the conductive adhesive 2 and the sheet-shaped electrode composition 1 previously cut were adhered to each other. Then, a tab 4 with an aluminum sealant 5 manufactured by Hosen Co., Ltd. was welded to the etched aluminum foil 3 using an ultrasonic welding machine. After welding, it was vacuum dried at 120 ° C. to obtain a polar electrode 6 provided with an aluminum current collector.
  • an aluminum laminated resin sheet manufactured by Hosen Co., Ltd. is cut into a rectangle (length 200 mm ⁇ width 60 mm), folded in half, and one side ((1) in FIG. 4) is thermocompression bonded.
  • a bag-shaped exterior sheet 7 having the remaining two sides open was prepared.
  • a laminated body in which two of the above polar electrodes 6 were laminated was produced via a cellulose separator "TF-40" (not shown) manufactured by Nippon Kodoshi Paper Industry Co., Ltd. This laminated body was inserted into the exterior sheet 7, and one side ((2) in FIG. 5) in contact with the tab 4 was thermocompression bonded to fix the polar electrode 6. Then, after vacuum-drying at 120 ° C.
  • the electrolytic solution was injected in a dry box with an argon atmosphere (dew point ⁇ 90 ° C. or lower).
  • an acetonitrile solution of 1.0 mol / L tetraethylammonium tetrafluoroborate manufactured by Kishida Scientific Co., Ltd. was used as the electrolytic solution. After impregnating the laminate with the electrolytic solution in the exterior sheet 7, the remaining one side ((3) in FIG. 5) of the exterior sheet 7 was thermocompression bonded to prepare the electrochemical device 8 shown in FIG.
  • the obtained electrochemical device 8 was charged at 25 ° C. and -30 ° C. using "CAPACITOR TESTER PFX2411" manufactured by Kikusui Electronics Co., Ltd. at a constant current of 50 mA per electrode surface surface up to a maximum voltage of 3.0 V. Further, the supplementary charge was performed at 3.0 V for 25 minutes under a constant voltage, and after the supplementary charge was completed, the battery was discharged at 25 mA.
  • the obtained discharge curve data was calculated by the energy conversion method and used as the capacitance (F). Specifically, after charging, the battery was discharged until the voltage became zero, and the capacitance (F) was calculated from the discharged energy discharged at this time. Then, the capacitance (F / g) obtained by dividing by the mass of the carbonaceous material of the electrode was obtained.
  • the amount of gas generated is measured by measuring the dry mass of the measurement electrode cell and the mass in water, determining the cell volume from the generated buoyancy and water density, and measuring the gas volume calculated from the change in cell volume before and after the durability test. It was corrected by the temperature difference of. That is, the amount of gas generated was calculated according to the following formula.
  • the cell mass A represents the cell mass (g) in air
  • the cell mass W represents the cell mass (g) in water.
  • Gas generation amount (cc) ⁇ (Cell mass A after endurance test-Cell mass W after endurance test) -(Cell mass A before durability test-Cell mass W before durability test) ⁇ / (273 + measured temperature after durability test (° C) / (273 + measured temperature before durability test (° C)))
  • the value obtained by further dividing the above gas generation amount by the carbonaceous material mass constituting the electrode composition was defined as the gas generation amount (cc / g) per carbonic material mass.
  • the electrochemical devices produced by using the polarization electrodes (1), (6), and (7) using the carbonaceous material of the present invention are comparative examples.
  • the initial capacitance is higher and the initial capacitance is maintained. At the same time, it is shown that the amount of gas generated is also suppressed.
  • the electrochemical device of the present invention suppresses a decrease in initial capacitance due to a decrease in specific surface area and pore volume, can maintain a sufficient capacitance even after a durability test, and has a high effect of suppressing gas generation. It has been shown.
  • Electrode composition 2 Conductive adhesive 3 Etched aluminum foil 4 Tabs 5 Sealant 6-minute polar electrode 7 Bag-shaped exterior sheet 8 Electrochemical device (1) Thermocompression-bonded side (2) One side where tabs touch (3) Bag-shaped The remaining side of the exterior sheet

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Abstract

The purpose of the present invention is to provide: a carbonaceous material with which an electrochemical device having a high initial capacitance, a high effect of reducing gas emissions during charging and discharging, and excellent durability can be obtained, and a method for producing the carbonaceous material; an electrode active material for an electrochemical device comprising the carbonaceous material; an electrode for an electrochemical device using the same; and an electrochemical device. The present invention relates to a carbonaceous material that has a BET specific surface area of 1550 to 2500 m2/g, a value of oxygen content/hydrogen content per specific surface area of 1.00 to 2.10 mg/m2, and a conductivity by powder resistivity measurement at a load of 12 kN of 10 to 15 S/cm.

Description

炭素質材料、その製造方法、電気化学デバイス用電極活物質、電気化学デバイス用電極および電気化学デバイスCarbonaceous materials, their manufacturing methods, electrode active materials for electrochemical devices, electrodes for electrochemical devices and electrochemical devices
　本発明は、炭素質材料、その製造方法、電気化学デバイス用電極活物質、電気化学デバイス用電極および電気化学デバイスに関する。 The present invention relates to a carbonaceous material, a method for producing the same, an electrode active material for an electrochemical device, an electrode for an electrochemical device, and an electrochemical device.
　電気化学デバイスの１つである電気二重層キャパシタは、化学反応を伴わず物理的なイオンの吸脱着のみから得られる容量（電気二重層容量）を利用しているため、電池と比較して出力特性および寿命特性に優れている。また、電気化学デバイスの１つであるリチウムイオンキャパシタは、電気二重層キャパシタのエネルギー密度を高めることができるハイブリッドキャパシタとして注目されている。近年では、これら電気化学デバイスの優れた特性と、環境問題への早急な対策といった点から、補助電源、回生エネルギーの貯蔵用途として電気自動車（ＥＶ）やハイブリッド自動車（ＨＶ）への搭載などでも注目されている。このような車載用の電気化学デバイスには、より高エネルギー密度であることだけでなく、民生用途と比較して厳しい使用条件下（たとえば厳しい温度環境下）における高い耐久性や静電容量のさらなる向上が求められている。 The electric double layer capacitor, which is one of the electrochemical devices, uses the capacity (electric double layer capacity) obtained only by the adsorption and desorption of physical ions without a chemical reaction, so it outputs more than the battery. Excellent in characteristics and life characteristics. A lithium ion capacitor, which is one of the electrochemical devices, is attracting attention as a hybrid capacitor capable of increasing the energy density of an electric double layer capacitor. In recent years, due to the excellent characteristics of these electrochemical devices and the urgent countermeasures against environmental problems, attention has been paid to the installation of auxiliary power sources and regenerative energy in electric vehicles (EV) and hybrid vehicles (HV). Has been done. Such automotive electrochemical devices not only have higher energy densities, but also have higher durability and capacitance under harsh usage conditions (eg, in harsh temperature environments) compared to consumer applications. Improvement is required.
　このような要求に対し、電気化学デバイスの耐久性や静電容量を改善させるための方法が種々検討されている。例えば、特許文献１および２には、静電容量を高め、且つ、耐久後のガス発生を抑えるために、粉砕前あるいは粉砕後の活性炭に対して高温で熱処理することが開示されている。また、特許文献３には、耐久性のさらなる向上等を目的として、高温下で活性炭を熱処理することにより活性炭の表面官能基量に加えて骨格内酸素量を制御することが記載されている。また、特許文献４には、アルカリ賦活によって得られる高比表面積化、且つ、高結晶化した活性炭の静電容量および耐久性の向上について記載されている。 In response to such demands, various methods for improving the durability and capacitance of electrochemical devices have been studied. For example, Patent Documents 1 and 2 disclose that activated carbon before or after pulverization is heat-treated at a high temperature in order to increase the capacitance and suppress gas generation after durability. Further, Patent Document 3 describes that the amount of oxygen in the skeleton is controlled in addition to the amount of surface functional groups of the activated carbon by heat-treating the activated carbon at a high temperature for the purpose of further improving the durability. Further, Patent Document 4 describes an increase in the specific surface area obtained by alkali activation and an improvement in the capacitance and durability of the highly crystallized activated carbon.
国際公開第２００８／０５３９１９号パンフレットInternational Publication No. 2008/05/3919 Pamphlet 特開２０１１－１１９３５号公報Japanese Unexamined Patent Publication No. 2011-11935 国際公開第２０１８／２０７７６９号パンフレットInternational Publication No. 2018/207769 Pamphlet 特開２０１７－１４７３３８号公報JP-A-2017-147338
　しかしながら、上記特許文献１および２に記載されるような高温下での熱処理は、活性炭の比表面積や細孔容積の低下を生じやすい。また、上記特許文献３に記載されるように、骨格内の酸素量を低減するために高温下で熱処理を行っても、骨格内の酸素とともに炭素外周部に存在している水素も低減するため比表面積や細孔容積の低下を生じやすい。このため、これらの文献に記載されるような活性炭は電気化学デバイスに使用する際の質量当たりおよび体積あたりの初期容量について必ずしも十分に満足のいくものではなかった。さらに、上記特許文献４に記載されるようなアルカリ賦活により得られる活性炭は賦活時、炭素量と同等以上の薬剤を加えることが一般的であり、アルカリ賦活後、残留する薬剤を取り除く工程が必要となる為、製造方法が煩雑となる。また水蒸気賦活で得られる活性炭と比較して、賦活時における官能基の量が多くなり、耐久性が低下する可能性がある。 However, the heat treatment at a high temperature as described in Patent Documents 1 and 2 is likely to cause a decrease in the specific surface area and pore volume of the activated carbon. Further, as described in Patent Document 3, even if the heat treatment is performed at a high temperature to reduce the amount of oxygen in the skeleton, the oxygen in the skeleton and the hydrogen existing in the outer periphery of the carbon are also reduced. The specific surface area and pore volume are likely to decrease. For this reason, activated carbons as described in these documents have not always been sufficiently satisfactory in terms of initial volume per mass and volume when used in electrochemical devices. Further, activated carbon obtained by alkali activation as described in Patent Document 4 generally has a chemical content equal to or higher than the amount of carbon added at the time of activation, and a step of removing residual chemicals after alkali activation is required. Therefore, the manufacturing method becomes complicated. Further, as compared with the activated carbon obtained by steam activation, the amount of functional groups at the time of activation is increased, and the durability may be lowered.
　本発明は、上記実状に鑑みてなされたものであり、初期静電容量が高く、充放電時のガス発生量の抑制効果が高く、且つ、耐久性にも優れた電気化学デバイスを得ることができる、炭素質材料およびその製造方法、前記炭素質材料からなる電気化学デバイス用電極活物質、それを用いた電気化学デバイス用電極並びに電気化学デバイスを提供することを目的とする。 The present invention has been made in view of the above circumstances, and it is possible to obtain an electrochemical device having a high initial capacitance, a high effect of suppressing the amount of gas generated during charging / discharging, and excellent durability. It is an object of the present invention to provide a carbonaceous material and a method for producing the same, an electrode active material for an electrochemical device made of the carbonaceous material, an electrode for an electrochemical device using the same, and an electrochemical device.
　本発明者等は、上記課題を解決するために、炭素質材料およびその製造方法について詳細に検討を重ねた結果、本発明に到達した。 The present inventors have arrived at the present invention as a result of repeated detailed studies on carbonaceous materials and methods for producing the same in order to solve the above problems.
　すなわち、本発明は、以下の好適な態様を包含する。
〔１〕ＢＥＴ比表面積が１５５０～２５００ｍ２／ｇであり、比表面積あたりの酸素含量／水素含量の値が１．００～２．１０ｍｇ／ｍ２であり、荷重１２ｋＮにおける粉体抵抗測定による導電率が１０～１５Ｓ／ｃｍである炭素質材料。
〔２〕酸素含量／水素含量の値が２．０～４．３である、前記〔１〕に記載の炭素質材料。
〔３〕炭素質材料が植物由来の炭素前駆体に基づく、前記〔１〕または〔２〕に記載の炭素質材料。
〔４〕炭素前駆体が椰子殻由来である、前記〔１〕～〔３〕のいずれかに記載の炭素質材料。
〔５〕炭素質材料前駆体を３３０℃以上に酸化性ガス雰囲気下で加熱する加熱工程と、酸化性ガス雰囲気下で３３０℃以上に加熱された炭素質材料前駆体を非酸化性ガス雰囲気下で降温する降温工程とを含み、
　前記酸化性ガス雰囲気下で実施される加熱工程が１回含まれる場合には、前記加熱工程に続けて前記降温工程が実施され、
　前記酸化性ガス雰囲気下で実施される加熱工程が複数回含まれる場合には、少なくとも最終の酸化性ガス雰囲気下で実施される加熱工程に続けて前記降温工程が実施され、
　最終の酸化性ガス雰囲気下で実施される加熱工程に供される炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍである、炭素質材料の製造方法。
〔６〕前記降温工程において、炭素質材料前駆体の温度を２００℃以下まで降温する、前記〔５〕に記載の炭素質材料の製造方法。
〔７〕前記〔１〕～〔４〕のいずれかに記載の炭素質材料から形成される電気化学デバイス用電極活物質。
〔８〕前記〔７〕に記載の電気化学デバイス用電極活物質含む電気化学デバイス用電極。
〔９〕前記〔８〕に記載の電気化学デバイス用電極を備える電気化学デバイス。 That is, the present invention includes the following preferred embodiments.
[1] The BET specific surface area is 1550 to 2500 m 2 / g, the oxygen content / hydrogen content value per specific surface area is 1.00 to 2.10 mg / m 2 , and the conductivity is measured by powder resistance at a load of 12 kN. A carbonaceous material with a specific surface area of 10 to 15 S / cm.
[2] The carbonaceous material according to the above [1], wherein the oxygen content / hydrogen content value is 2.0 to 4.3.
[3] The carbonaceous material according to the above [1] or [2], wherein the carbonaceous material is based on a plant-derived carbon precursor.
[4] The carbonaceous material according to any one of [1] to [3] above, wherein the carbon precursor is derived from coconut shell.
[5] A heating step of heating the carbonaceous material precursor to 330 ° C. or higher in an oxidizing gas atmosphere, and a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere under a non-oxidizing gas atmosphere. Including the temperature lowering process of lowering the temperature with
When the heating step performed in the oxidizing gas atmosphere is included once, the temperature lowering step is carried out following the heating step.
When the heating step performed in the oxidizing gas atmosphere is included a plurality of times, at least the heating step performed in the final oxidizing gas atmosphere is followed by the temperature lowering step.
A method for producing a carbonaceous material, wherein the conductivity measured by powder resistance measurement of a carbonaceous material precursor to be subjected to a heating step performed in a final oxidizing gas atmosphere at a load of 12 kN is 11 to 16 S / cm.
[6] The method for producing a carbonaceous material according to the above [5], wherein the temperature of the carbonaceous material precursor is lowered to 200 ° C. or lower in the temperature lowering step.
[7] An electrode active material for an electrochemical device formed from the carbonaceous material according to any one of the above [1] to [4].
[8] Electrode for an electrochemical device according to the above [7] Electrode for an electrochemical device containing an active material.
[9] An electrochemical device including the electrode for the electrochemical device according to the above [8].
　本発明によれば、初期静電容量が高く、充放電時のガス発生量の抑制効果が高く、且つ、耐久性に優れた電気化学デバイスを得ることができる、炭素質材料およびその製造方法、前記炭素質材料からなる電気化学デバイス用電極活物質、それを用いた電気化学デバイス用電極並びに電気化学デバイスを提供することができる。 According to the present invention, a carbonaceous material and a method for producing the same, which can obtain an electrochemical device having a high initial capacitance, a high effect of suppressing the amount of gas generated during charging / discharging, and excellent durability. It is possible to provide an electrode active material for an electrochemical device made of the carbonaceous material, an electrode for an electrochemical device using the same, and an electrochemical device.
シート状の電極組成物を示す図である。It is a figure which shows the sheet-shaped electrode composition. 導電性接着剤が塗布された集電体（エッチングアルミニウム箔）を示す図である。It is a figure which shows the current collector (etched aluminum foil) coated with a conductive adhesive. シート状の電極組成物と集電体を接着しアルミニウム製タブを超音波溶接した分極性電極を示す図である。It is a figure which shows the polar electrode which bonded the sheet-like electrode composition and the current collector, and ultrasonically welded the aluminum tab. 袋状の外装シートを示す図である。It is a figure which shows the bag-shaped exterior sheet. 電気化学デバイスを示す図である。It is a figure which shows the electrochemical device.
　以下、本発明の実施の形態について詳細に説明する。なお、本発明の範囲はここで説明する実施の形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で種々の変更をすることができる。
　なお、本発明においては、前記降温工程における降温処理を行う前の炭素質物質を「炭素質材料前駆体」といい、炭素質材料前駆体に前記最終加熱処理を行い、前記降温処理を施すことにより得られる炭素質物質を「炭素質材料」という。また、本明細書において、原料となる炭素前駆体の炭化物を、該炭化物を賦活処理することにより得られる炭素質物質（活性炭）と区別して「炭化物」という場合があるが、本発明における「炭素質材料前駆体」には、原料となる炭素前駆体の炭化物や、炭化物を賦活処理することにより得られる炭素質物質（活性炭）などの、前記降温処理を行う前の炭素質物質が広く含まれる。 Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.
In the present invention, the carbonaceous substance before the temperature lowering treatment in the temperature lowering step is referred to as "carbonaceous material precursor", and the carbonaceous material precursor is subjected to the final heat treatment and the temperature lowering treatment is performed. The carbonaceous material obtained by the above is called "carbonaceous material". Further, in the present specification, the carbide of the carbon precursor as a raw material may be referred to as "carbide" to distinguish it from the carbonaceous substance (activated carbon) obtained by activating the carbonaceous substance, but the "carbon" in the present invention may be used. The "quality material precursor" broadly includes carbonaceous substances before the temperature lowering treatment, such as carbides of carbon precursors as raw materials and carbonaceous substances (activated carbon) obtained by activating the carbides. ..
［炭素質材料］
　本発明の炭素質材料において、ＢＥＴ比表面積は１５５０～２５００ｍ２／ｇであり、比表面積あたりの水素含量／酸素含量の値は１．００～２．１０ｍｇ／ｍ２であり、荷重１２ｋＮにおける粉体抵抗測定による導電率が１０～１５Ｓ／ｃｍである。 [Carbonous material]
In the carbonaceous material of the present invention, the BET specific surface area is 1550 to 2500 m 2 / g, the value of hydrogen content / oxygen content per specific surface area is 1.00 to 2.10 mg / m 2 , and the powder under a load of 12 kN. The conductivity measured by body resistance is 10 to 15 S / cm.
　本発明の炭素質材料のＢＥＴ比表面積は、１５５０ｍ２／ｇ以上であり、１６００ｍ２／ｇ以上であることが好ましく、また、２５００ｍ２／ｇ以下であり、２４５０ｍ２／ｇ以下であることが好ましく、２４００ｍ２／ｇ以下であることがより好ましい。一般に、単位面積あたりの静電容量は一定である。そのため、ＢＥＴ比表面積が１５５０ｍ２／ｇ未満であると、単位質量あたりの静電容量を十分に高めることが難しい。また、平均細孔径が相対的に小さいため、大電流下における充放電時に細孔内での非水系電解質イオンの拡散抵抗によると思われる抵抗が大きくなる傾向にある。一方で、ＢＥＴ比表面積が２５００ｍ２／ｇを超えると、該炭素質材料を用いて製造した電極の嵩密度が低くなり、体積あたりの静電容量が低くなる傾向がある。 BET specific surface area of the carbonaceous material of the present invention is 1550 m 2 / g or more, preferably 1600 m 2 / g or more, and not more than 2500 m 2 / g, not more than 2450m 2 / g It is preferably 2400 m 2 / g or less, more preferably 2400 m 2 / g or less. Generally, the capacitance per unit area is constant. Therefore, if the BET specific surface area is less than 1550 m 2 / g, it is difficult to sufficiently increase the capacitance per unit mass. In addition, since the average pore diameter is relatively small, the resistance that is thought to be due to the diffusion resistance of non-aqueous electrolyte ions in the pores tends to increase during charging and discharging under a large current. On the other hand, when the BET specific surface area exceeds 2500 m 2 / g, the bulk density of the electrode manufactured by using the carbonaceous material tends to be low, and the capacitance per volume tends to be low.
　本発明の炭素質材料は、比表面積あたりの酸素含量（質量％）／水素含量（質量％）の値が（以下、単に「比表面積あたりのＯ／Ｈ」と記載する場合がある。）１．００ｍｇ／ｍ２以上であり、１．１０ｍｇ／ｍ２以上であることが好ましく、１．２０ｍｇ／ｍ２以上であることがより好ましく、また、２．１０ｍｇ／ｍ２以下であり、２．０８ｍｇ／ｍ２以下であることが好ましく、２．０６ｍｇ／ｍ２以下であることがより好ましい。本発明において「酸素含量、Ｏ」とは、後述される元素分析の測定結果から得られる炭素質材料中の酸素質量を示しており、炭素質材料表面に存在している表面酸素量と、骨格内に組み込まれて存在する酸素量との総和を示す。また「水素含量、Ｈ」は、炭素質材料の炭素結晶外周部に存在している水素量を示す。ここで炭素質材料表面に存在している表面酸素量は、耐久性悪化やガス発生の一因とされる官能基の程度を表し、炭素質材料の骨格内に組み込まれて存在する酸素量と、結晶外周部に存在している水素量は、炭素結晶構造の発達度合いを表す。従って、比表面積あたりのＯ／Ｈは炭素質材料の炭素結晶の成長を抑え、且つ、耐久性やガス発生の観点からの適正な酸素量を示すための指標となる。そのため、比表面積あたりのＯ／Ｈが上記下限値以上であると、炭素質材料表面の酸素が適度に存在している状態でありバインダーとの親和性が向上すると推測され、電極成形性に優れる。また、炭素質材料の炭素構造が十分に発達した状態であり結晶性が高いことにより炭素質材料自身の電気伝導率が向上すると推測される。一方で、比表面積あたりのＯ／Ｈが上記上限値以下であれば、炭素質材料表面に存在している表面酸素量が適度に低下した状態であり、充放電時のガス発生が抑制されると推測される。また、炭素質材料の炭素結晶構造の過度な発達を抑制でき、それに伴う炭素質材料の細孔の収縮が抑制されると推測され、質量当たりの初期静電容量の低下を抑制しやすい。なお、本発明における比表面積あたりのＯ／Ｈの値は、後述する実施例に記載の方法に従い算出される値である。 The carbonaceous material of the present invention has a value of oxygen content (mass%) / hydrogen content (mass%) per specific surface area (hereinafter, may be simply referred to as "O / H per specific surface area") 1 and a .00mg / m 2 or more, preferably 1.10 mg / m 2 or more, more preferably 1.20 mg / m 2 or more, and at 2.10mg / m 2 or less, 2. preferably 08mg / m 2 or less, more preferably 2.06 mg / m 2 or less. In the present invention, "oxygen content, O" indicates the mass of oxygen in the carbonaceous material obtained from the measurement results of elemental analysis described later, and the amount of surface oxygen existing on the surface of the carbonaceous material and the skeleton. Shows the sum of the amount of oxygen incorporated and present. Further, "hydrogen content, H" indicates the amount of hydrogen present on the outer periphery of the carbon crystal of the carbonaceous material. Here, the amount of surface oxygen present on the surface of the carbonaceous material represents the degree of functional groups that contribute to the deterioration of durability and gas generation, and the amount of oxygen present in the skeleton of the carbonaceous material. , The amount of hydrogen present on the outer periphery of the crystal represents the degree of development of the carbon crystal structure. Therefore, the O / H per specific surface area is an index for suppressing the growth of carbon crystals of the carbonaceous material and showing an appropriate amount of oxygen from the viewpoint of durability and gas generation. Therefore, when the O / H per specific surface area is equal to or higher than the above lower limit value, it is presumed that oxygen on the surface of the carbonaceous material is appropriately present and the affinity with the binder is improved, and the electrode moldability is excellent. .. In addition, it is presumed that the carbon structure of the carbonaceous material is sufficiently developed and the crystallinity is high, so that the electrical conductivity of the carbonaceous material itself is improved. On the other hand, if the O / H per specific surface area is not more than the above upper limit value, the amount of surface oxygen existing on the surface of the carbonaceous material is appropriately reduced, and gas generation during charging / discharging is suppressed. It is presumed. Further, it is presumed that the excessive development of the carbon crystal structure of the carbonaceous material can be suppressed, and the shrinkage of the pores of the carbonaceous material accompanying the suppression can be suppressed, and it is easy to suppress the decrease in the initial capacitance per mass. The value of O / H per specific surface area in the present invention is a value calculated according to the method described in Examples described later.
　本発明の炭素質材料は、荷重１２ｋＮにおける粉体抵抗測定による導電率が１０Ｓ／ｃｍ以上であり、１０．５Ｓ／ｃｍ以上であることが好ましく、１１以上であることがより好ましく、また、１５Ｓ／ｃｍ以下であり、１４．５Ｓ／ｃｍ以下であることが好ましく、１４Ｓ／ｃｍ以下であることがより好ましい。荷重１２ｋＮにおける粉体抵抗測定による導電率が上記上限値以下であると、炭素質材料の炭素結晶構造の過度な発達を抑制することができ、それに伴う炭素質材料の細孔の収縮を抑制できるため、質量当たりの初期静電容量の低下が抑制されると推測される。一方で、荷重１２ｋＮにおける粉体抵抗測定による導電率が上記下限値以上であると、炭素質材料の炭素結晶構造の発達が十分に発達した状態であり結晶性が高いことにより、炭素自身の電気伝導度が向上することで、充放電時の電流漏れによる抵抗増加を抑制でき、容量維持率を向上させると推測される。 The carbonaceous material of the present invention has a conductivity of 10 S / cm or more, preferably 10.5 S / cm or more, more preferably 11 or more, and 15 S, as measured by powder resistance at a load of 12 kN. It is / cm or less, preferably 14.5 S / cm or less, and more preferably 14 S / cm or less. When the conductivity measured by powder resistance measurement at a load of 12 kN is not more than the above upper limit value, excessive development of the carbon crystal structure of the carbonaceous material can be suppressed, and the accompanying shrinkage of pores of the carbonaceous material can be suppressed. Therefore, it is presumed that the decrease in the initial capacitance per mass is suppressed. On the other hand, when the conductivity measured by powder resistance measurement at a load of 12 kN is equal to or higher than the above lower limit value, the carbon crystal structure of the carbonaceous material is sufficiently developed and the crystallinity is high, so that the electricity of the carbon itself is high. It is presumed that the improvement in conductivity can suppress the increase in resistance due to current leakage during charging and discharging, and improve the capacity retention rate.
　本発明の炭素質材料の平均細孔径は、好ましくは１．７５ｎｍ以上、より好ましくは１．７８ｎｍ以上、さらに好ましくは１．８０ｎｍ以上である。平均細孔径が上記下限値以上であると、大電流下における充放電時に細孔内での非水系電解質イオンの拡散抵抗によると思われる抵抗が小さくなる傾向にある。また、本発明の炭素質材料の平均細孔径は、好ましくは２．６０ｎｍ以下、より好ましくは２．５５ｎｍ以下、さらに好ましくは２．５０ｎｍ以下である。平均細孔径が上記上限値以下であると、該炭素質材料を用いて製造した電極の嵩密度が高くなり、体積当たりの静電容量が高くなる傾向がある。炭素質材料のＢＥＴ比表面積および平均細孔径を、それぞれ上記上下限値の範囲に制御することにより、単位質量および体積当たりの高い静電容量を確保し、かつ、抵抗の小さい電気化学デバイスを得るのにより適した炭素質材料を得ることができる。なお、平均細孔径は、後述する実施例に記載の方法により測定することができる。 The average pore diameter of the carbonaceous material of the present invention is preferably 1.75 nm or more, more preferably 1.78 nm or more, still more preferably 1.80 nm or more. When the average pore diameter is at least the above lower limit value, the resistance that is considered to be due to the diffusion resistance of non-aqueous electrolyte ions in the pores tends to decrease during charging / discharging under a large current. The average pore diameter of the carbonaceous material of the present invention is preferably 2.60 nm or less, more preferably 2.55 nm or less, still more preferably 2.50 nm or less. When the average pore diameter is not more than the above upper limit value, the bulk density of the electrode manufactured by using the carbonaceous material tends to be high, and the capacitance per volume tends to be high. By controlling the BET specific surface area and the average pore diameter of the carbonaceous material within the above upper and lower limit values, respectively, an electrochemical device having a high capacitance per unit mass and volume and a low resistance can be obtained. A more suitable carbonaceous material can be obtained. The average pore diameter can be measured by the method described in Examples described later.
　また、本発明の炭素質材料の全細孔容積は、好ましくは０．７０ｃｍ３／ｇ以上であり、より好ましくは０．７２ｃｍ３／ｇ以上である。全細孔容積が上記下限値以上であると、大電流下における充放電時に細孔内での非水系電解質イオンの拡散抵抗によると思われる抵抗が小さくなる傾向にある。また、本発明の炭素質材料の全細孔容積は、好ましくは１．３０ｃｍ３／ｇ以下であり、より好ましくは１．２９ｃｍ３／ｇ以下であり、さらに好ましくは１．２８ｃｍ３／ｇ以下である。全細孔容積が上記上限値以下であると、該炭素質材料を用いて製造した電極の嵩密度が高くなり、体積当たりの静電容量が高くなる傾向がある。なお、全細孔容積は、後述する実施例に記載の方法により測定することができる。 The total pore volume of the carbonaceous material of the present invention is preferably 0.70 cm 3 / g or more, and more preferably 0.72 cm 3 / g or more. When the total pore volume is at least the above lower limit value, the resistance that is considered to be due to the diffusion resistance of the non-aqueous electrolyte ion in the pores tends to decrease during charging / discharging under a large current. The total pore volume of the carbonaceous material of the present invention is preferably 1.30 cm 3 / g or less, more preferably 1.29 cm 3 / g or less, and further preferably 1.28 cm 3 / g or less. Is. When the total pore volume is not more than the above upper limit value, the bulk density of the electrode manufactured by using the carbonaceous material tends to be high, and the capacitance per volume tends to be high. The total pore volume can be measured by the method described in Examples described later.
　本発明の炭素質材料は、酸素含量（質量％）／水素含量（質量％）の値が２．０以上であることが好ましく、２．２５以上であることがより好ましく、２．５以上であることがさらに好ましく、２．６以上であることが特に好ましく、２．７以上であることがより特に好ましく、また、４．３以下であることが好ましく、４．２以下であることがより好ましく、４．１以下であることがさらに好ましい。上記範囲内であると、ガスの発生抑制効果や静電容量の低下抑制効果をより高めることができる。 The carbonaceous material of the present invention preferably has an oxygen content (% by mass) / hydrogen content (mass%) of 2.0 or more, more preferably 2.25 or more, and 2.5 or more. It is more preferably 2.6 or more, particularly preferably 2.7 or more, more preferably 4.3 or less, and more preferably 4.2 or less. It is preferable, and it is more preferably 4.1 or less. Within the above range, the effect of suppressing the generation of gas and the effect of suppressing the decrease in capacitance can be further enhanced.
　本発明の炭素質材料の平均粒子径は、３０μｍ以下であることが好ましく、２０μｍ以下であることがより好ましく、また、２μｍ以上であることが好ましく、４μｍ以上であることがより好ましい。上記範囲内であると、該炭素質材料を用いて製造した電極の薄層化を可能とし、また、嵩密度が向上し、体積あたりの静電容量が高くなる傾向がある。なお本発明における平均粒子径の値は、後述する実施例に記載の方法に従い算出される値である。 The average particle size of the carbonaceous material of the present invention is preferably 30 μm or less, more preferably 20 μm or less, preferably 2 μm or more, and more preferably 4 μm or more. When it is within the above range, the electrode manufactured by using the carbonaceous material can be thinned, the bulk density is improved, and the capacitance per volume tends to be high. The value of the average particle size in the present invention is a value calculated according to the method described in Examples described later.
［炭素質材料の製造方法］
　本発明の炭素質材料は、例えば、
　炭素質材料前駆体を３３０℃以上に酸化性ガス雰囲気下で加熱する加熱工程と、酸化性ガス雰囲気下で３３０℃以上に加熱された炭素質材料前駆体を非酸化性ガス雰囲気下で降温する降温工程とを含み、
　前記酸化性ガス雰囲気下で実施される加熱工程が１回含まれる場合には、前記加熱工程に続けて前記降温工程が実施され、
　前記酸化性ガス雰囲気下で実施される加熱工程が複数回含まれる場合には、少なくとも最終の酸化性ガス雰囲気下で実施される加熱工程に続けて前記降温工程が実施され、
　最終の酸化性ガス雰囲気下で実施される加熱工程に供される炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍである、
方法により製造することができる。 [Manufacturing method of carbonaceous material]
The carbonaceous material of the present invention is, for example,
A heating step in which the carbonaceous material precursor is heated to 330 ° C. or higher in an oxidizing gas atmosphere, and a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere is cooled in a non-oxidizing gas atmosphere. Including the temperature lowering process
When the heating step performed in the oxidizing gas atmosphere is included once, the temperature lowering step is carried out following the heating step.
When the heating step performed in the oxidizing gas atmosphere is included a plurality of times, at least the heating step performed in the final oxidizing gas atmosphere is followed by the temperature lowering step.
The conductivity of the carbonaceous material precursor subjected to the heating step carried out in the final oxidizing gas atmosphere by measuring the powder resistance at a load of 12 kN is 11 to 16 S / cm.
It can be manufactured by the method.
　前記酸化性ガス雰囲気下で実施される加熱工程が１回含まれる場合には、前記加熱工程に続けて前記降温工程が実施され、前記酸化性ガス雰囲気下で実施される加熱工程が複数回含まれる場合には、少なくとも最終の酸化性ガス雰囲気下で実施される加熱工程に続けて前記降温工程が実施される。本発明において、炭素質材料前駆体を酸化性ガス雰囲気下で３３０℃以上に加熱する最終の加熱工程後に続けて該炭素質材料前駆体を非酸化性ガス雰囲気下で冷却することにより、細孔収縮を抑制しながら、得られる炭素質材料の表面に存在する表面酸素量および骨格内酸素量を低減することができる。 When the heating step carried out in the oxidizing gas atmosphere is included once, the temperature lowering step is carried out following the heating step, and the heating step carried out in the oxidizing gas atmosphere is included a plurality of times. If so, the temperature lowering step is carried out at least following the heating step carried out in the final oxidizing gas atmosphere. In the present invention, the pores are formed by cooling the carbonaceous material precursor in a non-oxidizing gas atmosphere following the final heating step of heating the carbonic material precursor to 330 ° C. or higher in an oxidizing gas atmosphere. It is possible to reduce the amount of surface oxygen and the amount of oxygen in the skeleton present on the surface of the obtained carbonaceous material while suppressing shrinkage.
　上記製造方法において、酸化性ガス雰囲気下で実施される加熱工程としては、例えば原料である炭素前駆体の炭化物を賦活する賦活工程や、必要に応じて不純物を除去する酸洗浄工程後に行われる、脱酸工程などが挙げられる。賦活工程は目的とする比表面積を得るため、１段階で実施してもよく、２段階以上に分けて実施してもよい。また、物質内の不純物を除去する酸洗浄は、賦活終了後に実施してもよく、多段階賦活の途中に実施してもよく、数回繰り返して実施することも可能である。酸洗浄後、細孔内に残留する酸成分、例えば、塩素分を除去するために、加熱処理（脱酸工程）を行うことが好ましい。本発明においては、炭素質材料前駆体を酸化性ガス雰囲気下で３３０℃以上に加熱する工程のうち最終の加熱工程終了後の降温過程において、非酸化性ガス雰囲気下で炭素質材料前駆体を冷却することが重要である。なお、酸化性ガス雰囲気下で実施される前記加熱工程が複数回行われる場合、最終の加熱工程により３３０℃以上に加熱された炭素質材料前駆体の降温工程以外の降温（冷却）は、非酸化性雰囲気下で行ってもよいし、酸化性ガス雰囲気下で行ってもよい。また、本発明の炭素質材料の製造方法は、最終の酸化性ガス雰囲気下で実施される加熱工程により３３０℃以上に加熱された炭素質材料前駆体の降温を非酸化性ガス雰囲気下で実施した後に、本発明の効果に影響を及ぼさない限りにおいて非酸化性ガス雰囲気下での加熱を含んでいてもよい。しかしながら、加熱による細孔収縮を可能な限り回避するためには、本発明の製造方法に含まれる炭素質材料前駆体を３３０℃以上に加熱する工程のうち最終の加熱工程が酸化性ガス雰囲気下で行われ、それに続く降温過程が非酸化性ガス雰囲気下で行われることが好ましい。 In the above production method, the heating step carried out in an oxidizing gas atmosphere is carried out, for example, after an activation step of activating carbides of a carbon precursor as a raw material or an acid cleaning step of removing impurities if necessary. Examples include a deoxidizing step. The activation step may be carried out in one step or divided into two or more steps in order to obtain the desired specific surface area. Further, the acid cleaning for removing impurities in the substance may be carried out after the activation is completed, may be carried out during the multi-step activation, or may be carried out repeatedly several times. After the acid cleaning, it is preferable to perform a heat treatment (deoxidation step) in order to remove an acid component remaining in the pores, for example, chlorine. In the present invention, in the step of heating the carbonaceous material precursor to 330 ° C. or higher in an oxidizing gas atmosphere, in the temperature lowering process after the final heating step is completed, the carbonaceous material precursor is heated in a non-oxidizing gas atmosphere. It is important to cool. When the heating step performed in an oxidizing gas atmosphere is performed a plurality of times, the temperature lowering (cooling) other than the temperature lowering step of the carbonaceous material precursor heated to 330 ° C. or higher by the final heating step is not performed. It may be carried out in an oxidizing atmosphere, or may be carried out in an oxidizing gas atmosphere. Further, in the method for producing a carbonaceous material of the present invention, the temperature of the carbonaceous material precursor heated to 330 ° C. or higher by the heating step carried out in the final oxidizing gas atmosphere is lowered in a non-oxidizing gas atmosphere. After that, heating in a non-oxidizing gas atmosphere may be included as long as it does not affect the effect of the present invention. However, in order to avoid pore shrinkage due to heating as much as possible, the final heating step of the steps of heating the carbonaceous material precursor contained in the production method of the present invention to 330 ° C. or higher is under an oxidizing gas atmosphere. It is preferable that the temperature lowering process is carried out in a non-oxidizing gas atmosphere.
　また、前記製造方法において、最終の酸化性ガス雰囲気下で実施される加熱工程に供される炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率は、好ましくは１１～１６Ｓ／ｃｍである。最終の酸化性ガス雰囲気下で実施される加熱処理に供する段階で、炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍであると、該炭素質材料前駆体における高度な結晶化を有する炭素質材料が得られ、電気化学デバイス用の電極活物質の材料として用いた場合に高い容量維持率を発揮しやすく、耐久性が向上しやすい。これにより、初期静電容量が高く、充放電時のガス発生抑制効果に優れるとともに、高度に発達した結晶化構造に起因して、高い初期静電容量を長期間保持できる耐久性に優れた電気化学デバイスを作製し得る炭素質材料を得ることができる。なお、本発明の炭素質材料の製造方法において、酸化性ガス雰囲気下で実施される加熱工程が１回のみ含まれる場合には、該加熱工程が上記「最終の酸化性ガス雰囲気下で実施される加熱工程」となる。
　以下、各工程について詳細に記載する。 Further, in the above-mentioned production method, the conductivity of the carbonaceous material precursor subjected to the heating step carried out in the final oxidizing gas atmosphere by measuring the powder resistance at a load of 12 kN is preferably 11 to 16 S / cm. is there. When the conductivity of the carbonaceous material precursor measured by powder resistance at a load of 12 kN is 11 to 16 S / cm at the stage of being subjected to the heat treatment carried out in the final oxidizing gas atmosphere, the carbonaceous material precursor A carbonaceous material having a high degree of crystallization is obtained, and when used as a material for an electrode active material for an electrochemical device, a high capacity retention rate is likely to be exhibited and durability is likely to be improved. As a result, the initial capacitance is high, the gas generation suppression effect during charging and discharging is excellent, and due to the highly developed crystallized structure, electricity with excellent durability that can maintain a high initial capacitance for a long period of time. It is possible to obtain a carbonaceous material capable of producing a chemical device. In the method for producing a carbonaceous material of the present invention, when the heating step carried out in an oxidizing gas atmosphere is included only once, the heating step is carried out in the above-mentioned "final oxidizing gas atmosphere". It becomes a heating process.
Hereinafter, each step will be described in detail.
　本発明において、炭素質材料の原料となる炭素前駆体は、賦活することによって炭素質材料を形成するものであれば特に限定されず、植物由来の炭素前駆体、鉱物由来の炭素前駆体、天然素材由来の炭素前駆体および合成素材由来の炭素前駆体などから広く選択することができる。有害不純物を低減する観点、環境保護の観点および商業的な観点からは、本発明の炭素質材料は、植物由来の炭素前駆体に基づくものであることが好ましく、言い換えると、本発明の炭素質材料となる炭素前駆体が植物由来であることが好ましい。 In the present invention, the carbon precursor used as a raw material for the carbonaceous material is not particularly limited as long as it forms the carbonaceous material by activation, and is a plant-derived carbon precursor, a mineral-derived carbon precursor, or a natural material. It can be widely selected from a carbon precursor derived from a material and a carbon precursor derived from a synthetic material. From the viewpoint of reducing harmful impurities, protecting the environment and from a commercial point of view, the carbonaceous material of the present invention is preferably based on a carbon precursor derived from a plant, in other words, the carbonaceous material of the present invention. It is preferable that the carbon precursor used as a material is derived from a plant.
　鉱物由来の炭素前駆体としては、例えば石油系および石炭系ピッチ、コークスが挙げられる。天然素材由来の炭素前駆体としては、例えば木綿、麻などの天然繊維、レーヨン、ビスコースレーヨンなどの再生繊維、アセテート、トリアセテートなどの半合成繊維が挙げられる。合成素材由来の炭素前駆体としては、例えばナイロンなどのポリアミド系、ビニロンなどのポリビニルアルコール系、アクリルなどのポリアクリロニトリル系、ポリエチレン、ポリプロピレンなどのポリオリフィン系、ポリウレタン、フェノール系樹脂、塩化ビニル系樹脂が挙げられる。 Examples of mineral-derived carbon precursors include petroleum-based and carbon-based pitches and coke. Examples of carbon precursors derived from natural materials include natural fibers such as cotton and hemp, regenerated fibers such as rayon and viscose rayon, and semi-synthetic fibers such as acetate and triacetate. Examples of carbon precursors derived from synthetic materials include polyamide-based resins such as nylon, polyvinyl alcohol-based resins such as vinylon, polyacrylonitrile-based resins such as acrylic, polyolifin-based resins such as polyethylene and polypropylene, polyurethane, phenol-based resins, and vinyl chloride-based resins. Can be mentioned.
　本発明において、植物由来の炭素前駆体としては、特に制限されないが、例えば椰子殻、珈琲豆、茶葉、サトウキビ、果実（例えば、みかん、バナナ）、藁、籾殻、広葉樹、針葉樹、竹が例示される。この例示は、本来の用途に供した後の廃棄物（例えば、使用済みの茶葉）、あるいは植物原料の一部（例えば、バナナやみかんの皮）を包含する。これらの植物原料を、単独で使用してもよいし、２種以上を組み合わせて使用してもよい。これらの植物原料の中でも、入手が容易で種々の特性を有する炭素質材料を製造できることから、椰子殻が好ましい。したがって、本明細書の炭素質材料は、植物由来の炭素前駆体に基づくものであることが好ましく、椰子殻由来の炭素前駆体に基づくものであることがより好ましい。 In the present invention, the plant-derived carbon precursor is not particularly limited, and examples thereof include palm husks, coffee beans, tea leaves, sugar cane, fruits (for example, mandarin oranges and bananas), straw, rice husks, hardwoods, conifers, and bamboo. To. This example includes waste after use for its intended purpose (eg, used tea leaves), or some plant material (eg, banana or tangerine peel). These plant raw materials may be used alone or in combination of two or more. Among these plant raw materials, coconut shells are preferable because they are easily available and carbonaceous materials having various properties can be produced. Therefore, the carbonaceous material of the present specification is preferably based on a plant-derived carbon precursor, and more preferably based on a coconut shell-derived carbon precursor.
　椰子殻としては、特に限定されないが、例えばパームヤシ（アブラヤシ）、ココヤシ、サラク、オオミヤシ等の椰子殻が挙げられる。これらの椰子殻を、単独で使用してもよいし、２種以上を組み合わせて使用してもよい。食品、洗剤原料、バイオディーゼル油原料等として椰子を利用した後に大量に発生するバイオマス廃棄物であるココヤシおよびパームヤシの椰子殻が、入手容易性の観点から特に好ましい。 The coconut shell is not particularly limited, and examples thereof include coconut husks such as palm palm (oil palm), coconut palm, salak, and lodoicea. These coconut shells may be used alone or in combination of two or more. Palm husks of coconut and palm palm, which are biomass wastes generated in large quantities after using coconut as a raw material for foods, detergents, biodiesel oil, etc., are particularly preferable from the viewpoint of availability.
［炭化工程］
　炭素前駆体から炭素質材料前駆体である炭化物を得る方法としては、特に限定されるものではなく、当該分野において既知の方法を用いて製造することができる。例えば、原料となる炭素前駆体を、窒素、二酸化炭素、ヘリウム、アルゴン、一酸化炭素もしくは燃料排ガスなどの不活性ガス、これら不活性ガスの混合ガス、またはこれら不活性ガスを主成分とする他のガスとの混合ガスの雰囲気下、４００～８００℃程度の温度で焼成（炭化処理）することによって製造することができる。炭化の方式としては、例えば、固定床方式、移動床方式、流動床方式、多段床方式、ロータリーキルンなどの公知の方式が採用できる。 [Carbonization process]
The method for obtaining the carbide, which is a carbonaceous material precursor, from the carbon precursor is not particularly limited, and can be produced by using a method known in the art. For example, the carbon precursor used as a raw material may be an inert gas such as nitrogen, carbon dioxide, helium, argon, carbon monoxide or fuel exhaust gas, a mixed gas of these inert gases, or a main component of these inert gases. It can be produced by firing (carbon dioxide treatment) at a temperature of about 400 to 800 ° C. in an atmosphere of a mixed gas with the above gas. As the carbonization method, for example, a known method such as a fixed floor method, a moving floor method, a fluidized bed method, a multi-stage floor method, or a rotary kiln can be adopted.
［賦活工程］
　本発明において、原料となる炭素質材料前駆体（活性炭）は、例えば、上記炭化物を賦活処理することにより得ることができる。賦活処理とは、炭化物の表面に細孔を形成し多孔質の炭素質物質に変える処理であり、これにより大きな比表面積および細孔容積を有する炭素質物質（炭素質材料前駆体）を得ることができる。賦活処理を行わず、炭化物をそのまま用いた場合には、得られる炭素質物質の比表面積や細孔容積が十分でなく、炭素結晶構造の発達も不十分となるため、電極材料に用いた場合に、十分に高い初期静電容量を確保することが困難であり、本発明の炭素質材料を得ることは困難である。賦活処理（賦活工程）は、通常炭化物を加熱することが必要であり、得られる炭素質材料前駆体は賦活工程に伴って３３０℃以上に加熱される。したがって、賦活工程は、本発明における加熱工程の一態様となり得る。賦活処理は、当該分野において一般的な方法により行うことができ、主に、ガス賦活処理と薬剤賦活処理の２種類の処理方法を挙げることができる。 [Activation process]
In the present invention, the carbonaceous material precursor (activated carbon) as a raw material can be obtained, for example, by activating the above-mentioned carbide. The activation treatment is a treatment of forming pores on the surface of a carbide and converting it into a porous carbonaceous substance, thereby obtaining a carbonaceous substance (carbonaceous material precursor) having a large specific surface area and pore volume. Can be done. When the carbide is used as it is without the activation treatment, the specific surface area and pore volume of the obtained carbonaceous substance are not sufficient, and the development of the carbon crystal structure is also insufficient. Therefore, when it is used as an electrode material. In addition, it is difficult to secure a sufficiently high initial capacitance, and it is difficult to obtain the carbonaceous material of the present invention. The activation treatment (activation step) usually requires heating of carbides, and the obtained carbonaceous material precursor is heated to 330 ° C. or higher in association with the activation step. Therefore, the activation step can be one aspect of the heating step in the present invention. The activation treatment can be carried out by a method general in the art, and there are mainly two types of treatment methods, a gas activation treatment and a chemical activation treatment.
　ガス賦活処理としては、例えば、水蒸気、二酸化炭素、空気、酸素、燃焼ガス、またはこれらの混合ガスの存在下、炭化物を加熱する方法が知られている。また、薬剤賦活処理としては、例えば、塩化亜鉛、塩化カルシウム、リン酸、硫酸、水酸化ナトリウム、水酸化カリウム、水酸化マグネシウム、水酸化カルシウムなどの賦活剤を炭素前駆体或いは炭素前駆体の炭化物と混合し、不活性ガス雰囲気下で加熱する方法が知られている。本発明においては、薬剤賦活は残留する薬剤を取り除く工程が必要となり、製造方法が煩雑となり、また賦活時における官能基の量も多くなるためガス賦活処理が好ましい。 As a gas activation treatment, for example, a method of heating carbides in the presence of water vapor, carbon dioxide, air, oxygen, combustion gas, or a mixed gas thereof is known. Further, as a chemical activation treatment, for example, an activator such as zinc chloride, calcium chloride, phosphoric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide is used as a carbon precursor or a carbide of the carbon precursor. There is known a method of mixing with and heating in an inert gas atmosphere. In the present invention, the drug activation requires a step of removing the residual drug, the production method becomes complicated, and the amount of functional groups at the time of activation increases, so that the gas activation treatment is preferable.
　ガス賦活処理として水蒸気賦活を採用する場合、効率良く賦活を進行させる観点から、炭化処理の際に用いたものと同様の不活性ガスと水蒸気との混合物を用いることが好ましく、その際の水蒸気の分圧は１０～６０％の範囲であることが好ましい。水蒸気分圧が１０％以上であると賦活を十分に進行させやすく、６０％以下であると、急激な賦活反応を抑制し、反応をコントロールしやすい。 When steam activation is adopted as the gas activation treatment, it is preferable to use a mixture of the same inert gas and steam as that used for the carbonization treatment from the viewpoint of efficiently advancing the activation, and the steam at that time The partial pressure is preferably in the range of 10 to 60%. When the partial pressure of water vapor is 10% or more, the activation is likely to proceed sufficiently, and when it is 60% or less, the rapid activation reaction is suppressed and the reaction is easy to control.
　水蒸気賦活において供給する賦活ガスの総量は、炭化物１００質量部に対して、５０～１００００質量部であることが好ましく、１００～５０００質量部であることがより好ましく、２００～３０００質量部であることがさらに好ましい。供給する賦活ガスの総量が上記範囲内であると、賦活反応をより効率よく進行させることができる。 The total amount of the activating gas supplied in the steam activation is preferably 50 to 10000 parts by mass, more preferably 100 to 5000 parts by mass, and 200 to 3000 parts by mass with respect to 100 parts by mass of the carbide. Is even more preferable. When the total amount of the activated gas to be supplied is within the above range, the activation reaction can proceed more efficiently.
　炭素質材料の比表面積や細孔容積は、炭化物の賦活処理方法およびその条件等を変えることにより制御することができる。例えば、水蒸気賦活処理により炭素質材料前駆体を得る場合、用いるガス種、濃度や加熱温度および反応時間等により制御することができる。本発明において、水蒸気賦活処理により炭素質材料前駆体を得る場合、その加熱温度（賦活温度）は用いるガスの種類にもよるが、通常７００～１１００℃であり、好ましくは８００～１０００℃、より好ましくは８５０～１０００℃である。 The specific surface area and pore volume of the carbonaceous material can be controlled by changing the method of activating the carbide and its conditions. For example, when a carbonaceous material precursor is obtained by steam activation treatment, it can be controlled by the gas type used, the concentration, the heating temperature, the reaction time, and the like. In the present invention, when a carbonaceous material precursor is obtained by steam activation treatment, the heating temperature (activation temperature) thereof is usually 700 to 1100 ° C., preferably 800 to 1000 ° C., although it depends on the type of gas used. It is preferably 850 to 1000 ° C.
　一般に、ガス賦活処理においては、反応性ガスを伴った状況下のもと炭化物を加熱することで脱炭反応（細孔形成）と結晶化とが進行するが、賦活時の反応速度を制御することにより、脱炭反応による細孔の形成よりも結晶化を促進させることができ、炭素結晶構造が十分に発達し、高い電気伝導率を有する炭素質材料前駆体（活性炭）を得ることができる。具体的には、所定の賦活温度下において、賦活時の反応速度が遅くなると、脱炭反応による細孔形成よりも結晶化が進みやすくなるため、粉体導電率が高くなり、容量維持率を向上させることができる。ここで本発明において、「賦活時の反応速度」とは、毎分当たりのＢＥＴ比表面積の増加量を意味する。炭素結晶構造が十分に発達した炭素質材料前駆体が得られる観点から、賦活時の反応速度は、例えば８５０～１０００℃の温度下で毎分当たり３．５ｍ2／ｇ以下であることが好ましく、３．０ｍ2／ｇ以下であることがより好ましく、また、０．５ｍ2／ｇ以上であることが好ましく、０．７５ｍ2／ｇ以上であることがより好ましい。毎分当たりのＢＥＴ比表面積の増加量が上記範囲内であると、細孔形成が比較的ゆっくりと、且つ、適当に進む間に結晶化がより進みやすくなるため、電気化学デバイス用の電極活物質の材料として用いた場合に高い容量維持率を発揮しやすく、耐久性が向上しやすい。なお、賦活処理が多段階の賦活工程により行われる場合、各段階における反応速度は製造設備や生産性等を考慮して適宜決定すればよいが、少なくとも一部において反応速度が上記範囲内であると、得られる炭素質材料前駆体の炭素結晶構造を制御しやすい。 Generally, in the gas activation treatment, decarburization reaction (pore formation) and crystallization proceed by heating the charcoal under a condition accompanied by a reactive gas, but the reaction rate at the time of activation is controlled. As a result, crystallization can be promoted rather than the formation of pores by the decarburization reaction, the carbon crystal structure is sufficiently developed, and a carbonaceous material precursor (activated carbon) having high electrical conductivity can be obtained. .. Specifically, when the reaction rate at the time of activation is slow under a predetermined activation temperature, crystallization is more likely to proceed than the formation of pores by the decarburization reaction, so that the powder conductivity becomes high and the capacity retention rate is increased. Can be improved. Here, in the present invention, the "reaction rate at the time of activation" means the amount of increase in the BET specific surface area per minute. From the viewpoint of obtaining a carbonaceous material precursor having a sufficiently developed carbon crystal structure, the reaction rate at the time of activation is preferably 3.5 m 2 / g or less per minute at a temperature of, for example, 850 to 1000 ° C. , 3.0 m 2 / g or less, more preferably 0.5 m 2 / g or more, and more preferably 0.75 m 2 / g or more. When the amount of increase in the BET specific surface area per minute is within the above range, the pore formation is relatively slow and the crystallization is more likely to proceed while the pore formation proceeds appropriately, so that the electrode activity for the electrochemical device When used as a material for materials, it tends to exhibit a high capacity retention rate and easily improve durability. When the activation treatment is carried out by a multi-step activation step, the reaction rate at each step may be appropriately determined in consideration of manufacturing equipment, productivity, etc., but the reaction rate is within the above range at least in a part. It is easy to control the carbon crystal structure of the obtained carbonaceous material precursor.
　前記賦活時の反応速度は、例えば、賦活処理を施す炭化物と賦活ガスとの接触条件（接触効率、賦活ガス種、賦活ガス量及び賦活ガス濃度／供給量など）、賦活温度、反応補助物質の種類、量、その状態（分散状態や塩組成）等を調整することにより制御できる。炭化物と賦活ガスとの接触条件は、賦活方式や賦活に用いる設備／機器、供給ガス量、濃度等により制御できる。本発明において賦活の方式は、上記賦活時の反応速度を達成し得るものを採用することが好ましい。例えば、通常、炭化物と賦活ガスとが滞留した状態で賦活が行われる縦型流動炉では、炭化物に賦活ガスが接触する頻度が高くなるため、脱炭反応が進みやすくなるのに対して、ロータリーキルンでは炭化物に賦活ガスが接触する頻度が低くなるため、脱炭反応が比較的ゆっくりと進み、それとともに結晶化がより進みやすくなる傾向にある。したがって、本発明の一態様において、賦活に用いる設備／機器としてロータリーキルンは好適である。 The reaction rate at the time of activation is, for example, the contact conditions (contact efficiency, activation gas type, activation gas amount and activation gas concentration / supply amount, etc.) between the carbide to be activated and the activation gas, the activation temperature, and the reaction auxiliary substance. It can be controlled by adjusting the type, amount, and its state (dispersion state and salt composition). The contact conditions between the carbide and the activation gas can be controlled by the activation method, the equipment / equipment used for activation, the amount of supplied gas, the concentration, and the like. In the present invention, it is preferable to adopt the activation method that can achieve the reaction rate at the time of activation. For example, in a vertical flow furnace in which activation is usually performed in a state where carbides and activation gas are retained, the frequency of contact of the activation gas with carbides is high, so that the decarburization reaction is easy to proceed, whereas a rotary kiln is used. In this case, since the activation gas comes into contact with the carbide less frequently, the decarburization reaction tends to proceed relatively slowly, and at the same time, crystallization tends to proceed more easily. Therefore, in one aspect of the present invention, the rotary kiln is suitable as the equipment / equipment used for activation.
　本発明の製造方法が加熱工程として賦活工程を含む場合、該賦活工程により得られる炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍとなるよう賦活処理を行うことが好ましい。賦活工程や脱酸工程など、炭素質材料の製造工程に含まれ得る複数の熱処理は、細孔形成や細孔収縮を生じるとともに炭素結晶構造の乱れを引き起こしやすい。乱れた炭素結晶構造を回復させることは困難であるため、炭素質材料を製造するための比較的初期の工程である賦活工程において、細孔形成と結晶化の進行を制御することにより炭素結晶構造を十分に発達させておくと、その後の工程においても該結晶構造を維持しやすく、高い電気伝導率を有する炭素質材料を得ることができる。なお、本発明の製造方法においては、既に賦活処理されている活性炭を出発材料として炭素質材料を製造してもよい。この場合においても、出発材料となる活性炭（炭素質材料前駆体）が高い粉体導電率を有していることが好ましく、荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍであることがより好ましい。 When the production method of the present invention includes an activation step as a heating step, the activation treatment is performed so that the conductivity of the carbonaceous material precursor obtained by the activation step is 11 to 16 S / cm by measuring the powder resistance at a load of 12 kN. Is preferable. A plurality of heat treatments that can be included in the production process of a carbonaceous material, such as an activation step and a deoxidation step, cause pore formation and pore shrinkage, and are likely to cause disorder of the carbon crystal structure. Since it is difficult to recover the disordered carbon crystal structure, the carbon crystal structure is controlled by controlling the pore formation and the progress of crystallization in the activation step, which is a relatively early step for producing a carbonaceous material. If the above is sufficiently developed, the crystal structure can be easily maintained even in the subsequent steps, and a carbonaceous material having high electrical conductivity can be obtained. In the production method of the present invention, a carbonaceous material may be produced using activated carbon that has already been activated as a starting material. Even in this case, it is preferable that the activated carbon (carbonaceous material precursor) as a starting material has a high powder conductivity, and the conductivity measured by powder resistance measurement at a load of 12 kN is 11 to 16 S / cm. Is more preferable.
［酸洗浄工程］
　本発明において、炭素質材料の製造方法は酸洗浄工程を含んでいてもよい。酸洗浄工程は、炭素質材料前駆体を、酸を含む洗浄液により洗浄することにより、炭素質材料前駆体中に含まれる金属成分等の不純物を除去するための工程である。酸洗浄工程は、賦活後に得られた炭素質材料前駆体を、酸を含む洗浄液に浸漬することによって行うことができる。洗浄液としては、例えば鉱酸または有機酸が挙げられる。鉱酸としては、例えば、塩酸、硫酸等が挙げられる。有機酸としては、例えば、ギ酸、酢酸、プロピオン酸、シュウ酸及び酒石酸、クエン酸等の飽和カルボン酸、安息香酸およびテレフタル酸等の芳香族カルボン酸等が挙げられる。洗浄液に用いる酸は、洗浄性の観点から、鉱酸であることが好ましく、塩酸であることがより好ましい。なお、酸を用いて洗浄を行った後、さらに水等を用いて洗浄して余剰の酸の除去を行うことが好ましい。この操作によって後工程での設備への負荷を軽減することができる。賦活工程が一次賦活工程を含む多段階賦活工程に分かれている場合は、酸洗浄工程は一次賦活工程後に行われてもよく、多段階賦活工程後に行われてもよい。 [Acid cleaning process]
In the present invention, the method for producing a carbonaceous material may include an acid cleaning step. The acid cleaning step is a step for removing impurities such as metal components contained in the carbonaceous material precursor by cleaning the carbonaceous material precursor with a cleaning liquid containing an acid. The acid cleaning step can be performed by immersing the carbonaceous material precursor obtained after activation in a cleaning solution containing an acid. Examples of the cleaning liquid include mineral acids and organic acids. Examples of the mineral acid include hydrochloric acid, sulfuric acid and the like. Examples of the organic acid include saturated carboxylic acids such as formic acid, acetic acid, propionic acid, oxalic acid and tartaric acid, and citric acid, and aromatic carboxylic acids such as benzoic acid and terephthalic acid. The acid used in the cleaning liquid is preferably a mineral acid, more preferably hydrochloric acid, from the viewpoint of detergency. It is preferable to perform washing with an acid and then further wash with water or the like to remove excess acid. By this operation, the load on the equipment in the subsequent process can be reduced. When the activation step is divided into a multi-step activation step including a primary activation step, the acid washing step may be carried out after the primary activation step or after the multi-step activation step.
　洗浄液は、通常、酸と水性溶液とを混合して調製することができる。水性溶液としては、水、水と水溶性有機溶媒との混合物などが挙げられる。水溶性有機溶媒としては、例えばメタノール、エタノール、プロピレングリコール、エチレングリコールなどのアルコールが挙げられる。 The cleaning solution can usually be prepared by mixing an acid and an aqueous solution. Examples of the aqueous solution include water and a mixture of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, propylene glycol and ethylene glycol.
　洗浄液中の酸の濃度は特に限定されるものではなく、用いる酸の種類に応じて濃度を適宜調整してよい。洗浄液の酸濃度は、洗浄液の総量に基づいて、０．１～３．０％であることが好ましく、０．３～１．０％であることがより好ましい。塩酸濃度が低過ぎると、不純物を除去するために酸洗回数を増やす必要があり、逆に高過ぎると、残留する塩酸が多くなることから、上記範囲の濃度とすることにより、効率よく酸洗浄工程を行うことができ、生産性の面から好ましい。 The concentration of the acid in the cleaning solution is not particularly limited, and the concentration may be appropriately adjusted according to the type of acid used. The acid concentration of the cleaning liquid is preferably 0.1 to 3.0%, more preferably 0.3 to 1.0%, based on the total amount of the cleaning liquid. If the hydrochloric acid concentration is too low, it is necessary to increase the number of picklings in order to remove impurities, and conversely, if the hydrochloric acid concentration is too high, the amount of residual hydrochloric acid increases. The process can be performed, which is preferable from the viewpoint of productivity.
　洗浄液のｐＨは、特に限定されるものではなく、用いる酸の種類や除去対象等に応じて適宜調節してよい。 The pH of the cleaning solution is not particularly limited, and may be appropriately adjusted according to the type of acid used, the object to be removed, and the like.
　酸洗や水洗をする際の液温度は特に限定されるものではないが、０～９８℃であることが好ましく、１０～９５℃であることがより好ましく、１５～９０℃であることがさらに好ましい。炭素質材料前駆体を浸漬する際の洗浄液の温度が上記範囲内であれば、実用的な時間かつ装置への負荷を抑制した洗浄の実施が可能となるため望ましい。 The liquid temperature for pickling or washing with water is not particularly limited, but is preferably 0 to 98 ° C, more preferably 10 to 95 ° C, and further preferably 15 to 90 ° C. preferable. When the temperature of the cleaning liquid when immersing the carbonaceous material precursor is within the above range, it is desirable that cleaning can be performed in a practical time and while suppressing the load on the apparatus.
　炭素質材料前駆体を洗浄液に浸漬する際の、洗浄液と炭素質材料前駆体との質量割合は、用いる洗浄液の種類、濃度および温度等に応じて適宜調節してよい。洗浄液の質量に対する、浸漬させる炭素質材料前駆体の質量は、通常０．１～５０質量％であり、１～２０質量％であることが好ましく、１．５～１０質量％であることがより好ましい。上記範囲内であれば、洗浄液に溶出した不純物が洗浄液から析出しにくく、炭素質材料前駆体への再付着を抑制しやすく、また、容積効率が適切となるため経済性の観点から望ましい。 When immersing the carbonaceous material precursor in the cleaning liquid, the mass ratio of the cleaning liquid and the carbonic material precursor may be appropriately adjusted according to the type, concentration, temperature, etc. of the cleaning liquid to be used. The mass of the carbonaceous material precursor to be immersed is usually 0.1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 1.5 to 10% by mass with respect to the mass of the cleaning liquid. preferable. Within the above range, impurities eluted in the cleaning liquid are less likely to precipitate from the cleaning liquid, reattachment to the carbonaceous material precursor is likely to be suppressed, and volumetric efficiency becomes appropriate, which is desirable from the viewpoint of economy.
　洗浄を行う雰囲気は特に限定されず、洗浄に使用する方法に応じて適宜選択してよい。本発明において洗浄は、通常、大気雰囲気中で実施する。 The atmosphere for cleaning is not particularly limited, and may be appropriately selected depending on the method used for cleaning. In the present invention, cleaning is usually carried out in an air atmosphere.
　洗浄は、１種の洗浄液で１回または複数回行ってもよいし、２種以上の洗浄液を組み合わせて複数回行ってもよい。 The cleaning may be performed once or multiple times with one type of cleaning liquid, or may be performed a plurality of times in combination of two or more types of cleaning liquids.
　炭素質材料前駆体を洗浄する方法としては、炭素質材料前駆体を洗浄液に浸漬させることができる限り特に限定されず、洗浄液を連続的に添加し、所定の時間滞留させ、抜き取りながら浸漬を行う方法でも、炭素質材料前駆体を洗浄液に浸漬し、所定の時間滞留させ、脱液した後、新たに洗浄液を添加して浸漬－脱液を繰り返す方法であってもよい。また、洗浄液の全部を更新する方法であってもよいし、洗浄液の一部を更新する方法であってもよい。炭素質材料前駆体を洗浄液に浸漬する時間としては、用いる酸、酸の濃度、処理温度等に応じて適宜調節することができる。 The method for cleaning the carbonaceous material precursor is not particularly limited as long as the carbonaceous material precursor can be immersed in the cleaning liquid, and the cleaning liquid is continuously added, retained for a predetermined time, and immersed while being withdrawn. The method may also be a method in which the carbonaceous material precursor is immersed in a cleaning solution, allowed to stay for a predetermined time, deliquesed, and then a new cleaning solution is added to repeat dipping and deliquescing. Further, it may be a method of renewing the entire cleaning liquid or a method of renewing a part of the cleaning liquid. The time for immersing the carbonaceous material precursor in the cleaning liquid can be appropriately adjusted according to the acid used, the concentration of the acid, the treatment temperature, and the like.
［脱酸工程］
　本発明において、炭素質材料の製造方法は、酸洗浄後に残留する酸洗浄液に由来する酸（例えば、塩酸等）を除去するための脱酸工程を含んでいてもよい。本発明において、脱酸工程は、酸洗浄後に酸化性ガス雰囲気下で炭素質材料前駆体を加熱することにより行うことができる。脱酸工程において、通常、炭素質材料前駆体は３３０℃以上に加熱されるため、脱酸工程は、本発明における加熱工程の一態様となり得る。また、酸化性ガスとの接触時間や温度を調整し、さらなる賦活反応を伴いながら残留する酸を除去することが可能である。脱酸工程が、酸化性ガス雰囲気下で実施される最終の加熱工程となる場合、該加熱工程に供される段階で炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍであることが好ましい。なお、通常、炭素質材料前駆体の粉体導電率は３３０℃以上の加熱処理を施すことによって変化し、かかる加熱処理を施さない限り大きく変化するものではないため、炭素質材料前駆体の粉体導電率の測定は採用する製造方法に含まれる各工程を考慮して行えばよく、必ずしも上記最終の酸化性ガス雰囲気下での加熱工程の直前である必要はない。例えば、先に説明したような賦活工程後、酸洗浄をし、最終の酸化性ガス雰囲気下での加熱処理として脱酸工程を行う場合には、脱酸工程より前に行われた加熱工程（すなわち、この場合は賦活工程）後から脱酸工程直前までの間に測定すればよい。 [Deoxidizing process]
In the present invention, the method for producing a carbonaceous material may include a deoxidizing step for removing an acid (for example, hydrochloric acid or the like) derived from an acid cleaning solution remaining after acid cleaning. In the present invention, the deoxidizing step can be carried out by heating the carbonaceous material precursor in an oxidizing gas atmosphere after acid cleaning. Since the carbonaceous material precursor is usually heated to 330 ° C. or higher in the deoxidizing step, the deoxidizing step can be one aspect of the heating step in the present invention. In addition, it is possible to adjust the contact time and temperature with the oxidizing gas to remove the residual acid with further activation reaction. When the deoxidizing step is the final heating step carried out in an oxidizing gas atmosphere, the conductivity measured by powder resistance measurement of the carbonaceous material precursor at a load of 12 kN at the stage of being subjected to the heating step is 11 to 11. It is preferably 16 S / cm. Normally, the powder conductivity of the carbonaceous material precursor changes by subjecting it to a heat treatment of 330 ° C. or higher, and does not change significantly unless such a heat treatment is performed. The body conductivity may be measured in consideration of each step included in the manufacturing method to be adopted, and does not necessarily have to be immediately before the final heating step in the oxidizing gas atmosphere. For example, in the case where acid cleaning is performed after the activation step as described above and the deoxidizing step is performed as the final heat treatment in an oxidizing gas atmosphere, the heating step performed before the deoxidizing step ( That is, in this case, the measurement may be performed from after the activation step) to immediately before the deoxidization step.
　酸化性ガスとしては、上記ガス賦活工程で用いられるガスを利用することができる。なお、本発明において「酸化性ガス雰囲気下」とは、容器内における炭素質材料前駆体あたりの酸化性ガスの総量が１．５Ｌ／ｋｇ以上の状態を意味する。 As the oxidizing gas, the gas used in the gas activation step can be used. In the present invention, "under an oxidizing gas atmosphere" means a state in which the total amount of oxidizing gas per carbonaceous material precursor in the container is 1.5 L / kg or more.
　上記処理温度としては、５００～１０００℃であることが好ましく、６５０～８５０℃であることがより好ましい。上記温度範囲内であると、炭素質材料前駆体の細孔構造に大きな変化を与えることなく脱酸できるため好ましい。時間は、温度によって異なるが、通常３０分～３時間程度である。 The treatment temperature is preferably 500 to 1000 ° C, more preferably 650 to 850 ° C. It is preferable that the temperature is within the above temperature range because deoxidation can be performed without significantly changing the pore structure of the carbonaceous material precursor. The time varies depending on the temperature, but is usually about 30 minutes to 3 hours.
　上記脱酸の方式は、特に限定されず、例えば、固定床方式、移動床方式、流動床方式、多段床方式、ロータリーキルンなどの公知の方式が採用できる。 The deoxidizing method is not particularly limited, and for example, a known method such as a fixed floor method, a moving floor method, a fluidized bed method, a multi-stage floor method, or a rotary kiln can be adopted.
　上記賦活工程あるいは脱酸工程において用いられる、炭素前駆体あるいはヤシガラ由来の炭素質材料前駆体の平均粒子径は、賦活、脱酸工程に応じて粒径を調整することができる。 The average particle size of the carbon precursor or the carbonaceous material precursor derived from coconut husk used in the activation step or the deoxidization step can be adjusted according to the activation and deoxidation steps.
［加熱後の降温工程］
　本発明の炭素質材料の製造方法は、酸化性ガス雰囲気下で３３０℃以上に加熱された炭素質材料前駆体を、非酸化性ガス雰囲気下で降温する降温工程を含む。すなわち、降温時の環境に存在する酸化性ガス（例えば酸素）と炭素表面の反応による官能基の形成を抑制するため、炭素質材料前駆体を酸化性ガス雰囲気下で３３０℃以上に加熱する工程のうち最終の加熱工程終了後の降温過程を、非酸化性ガス雰囲気下で行う工程を含む。これにより、本発明の炭素質材料を得ることができる。賦活処理後や脱酸工程後に、炭素質材料前駆体の表面に存在する酸性官能基を除去するために不活性ガス雰囲気下で炭素質材料前駆体を加熱する方法が知られているが、かかる方法では加熱により細孔収縮が生じやすく、電気化学デバイスに用いた際の十分に高い初期静電容量を確保することが困難な場合がある。また、加熱のためのさらなる工程が必要となったり、加熱条件を厳密に制御する必要性が生じたりするなど、生産性の面での課題もある。本発明においては、炭素質材料前駆体の表面に存在する酸性官能基や骨格内酸素を低減するための不活性ガス雰囲気下における原料炭素材料の加熱を必要としないため、細孔収縮を生じることなく初期静電容量の高い電気化学デバイスを作製し得る炭素質材料を得ることができる。 [Cooling process after heating]
The method for producing a carbonaceous material of the present invention includes a temperature lowering step of lowering the temperature of a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere in a non-oxidizing gas atmosphere. That is, a step of heating the carbonaceous material precursor to 330 ° C. or higher in an oxidizing gas atmosphere in order to suppress the formation of functional groups due to the reaction between the oxidizing gas (for example, oxygen) existing in the environment at the time of temperature decrease and the carbon surface. Of these, a step of lowering the temperature after the final heating step is performed in a non-oxidizing gas atmosphere is included. Thereby, the carbonaceous material of the present invention can be obtained. A method of heating a carbonaceous material precursor in an inert gas atmosphere in order to remove acidic functional groups present on the surface of the carbonaceous material precursor after an activation treatment or a deoxidation step is known. In the method, pore shrinkage is likely to occur due to heating, and it may be difficult to secure a sufficiently high initial capacitance when used in an electrochemical device. In addition, there are problems in terms of productivity, such as the need for further steps for heating and the need to strictly control the heating conditions. In the present invention, since it is not necessary to heat the raw material carbon material in an inert gas atmosphere to reduce the acidic functional groups existing on the surface of the carbonaceous material precursor and oxygen in the skeleton, pore shrinkage occurs. It is possible to obtain a carbonaceous material capable of producing an electrochemical device having a high initial capacitance.
　降温工程においては、最終の酸化性ガス雰囲気下で加熱処理された炭素質材料前駆体の温度を、非酸化性ガス雰囲気下で、好ましくは２００℃以下、より好ましくは１５０℃以下まで降温する。上記温度までの降温時間は降温環境に存在する酸化性ガスの量にもよるが、生産性も合わせ鑑みると３時間以内、好ましくは１時間以内が望ましい。また、間接冷却装置（たとえば冷却キルン等）を用い、降温速度を速め、炭素質材料前駆体が酸化されうる温度領域の時間を短縮することが酸化抑制、生産性の観点からより望ましい。 In the temperature lowering step, the temperature of the carbonaceous material precursor heat-treated in the final oxidizing gas atmosphere is lowered to preferably 200 ° C. or lower, more preferably 150 ° C. or lower in a non-oxidizing gas atmosphere. The temperature lowering time to the above temperature depends on the amount of oxidizing gas existing in the temperature lowering environment, but it is preferably within 3 hours, preferably within 1 hour in consideration of productivity. Further, it is more desirable from the viewpoint of oxidation suppression and productivity to use an indirect cooling device (for example, a cooling kiln) to increase the temperature lowering rate and shorten the time in the temperature region where the carbonaceous material precursor can be oxidized.
　非酸化性ガスとは、例えば、窒素ガス、乾燥水素ガス、アンモニアガス、アルゴンガス、ヘリウムガス、水素ガス、一酸化炭素ガス、炭化水素ガスが挙げられる。これらのガスは、１種類のみ単独で用いてもよく、また、２種類以上を混合した混合ガスとして用いてもよい。 Examples of the non-oxidizing gas include nitrogen gas, dry hydrogen gas, ammonia gas, argon gas, helium gas, hydrogen gas, carbon monoxide gas, and hydrocarbon gas. Only one kind of these gases may be used alone, or two or more kinds of these gases may be used as a mixed gas.
　非酸化性ガス雰囲気下とは、例えば空気等の酸化性ガスを多く含む雰囲気に比べ、酸化性ガスが大幅に低減された雰囲気下を意味する。具体的に、本発明において「非酸化性ガス雰囲気下」とは、容器内における炭素質材料前駆体あたりの酸化性ガスの総量が０．７Ｌ／ｋｇ以下の状態を意味する。本発明の効果をより高めるため、降温時の環境に存在する酸化性ガスの総量が炭素質材料前駆体あたり０．５Ｌ／Ｋｇ以下であることが好ましく、０．１Ｌ／Ｋｇ以下であることがより好ましい。上記範囲内であれば降温過程における、酸化性ガスと炭素表面の反応による官能基の形成を抑制することができる。 The non-oxidizing gas atmosphere means an atmosphere in which the oxidizing gas is significantly reduced as compared with an atmosphere containing a large amount of oxidizing gas such as air. Specifically, in the present invention, "under a non-oxidizing gas atmosphere" means a state in which the total amount of oxidizing gas per carbonaceous material precursor in the container is 0.7 L / kg or less. In order to further enhance the effect of the present invention, the total amount of oxidizing gas present in the environment at the time of lowering temperature is preferably 0.5 L / Kg or less, and preferably 0.1 L / Kg or less per carbonaceous material precursor. More preferred. Within the above range, the formation of functional groups due to the reaction between the oxidizing gas and the carbon surface in the temperature lowering process can be suppressed.
［粉砕工程］
　本発明において、炭素質材料の製造方法は粉砕工程を含んでいてもよい。粉砕工程は、最終的に得られる炭素質材料の形状や粒径を所望する形状や粒径に制御するための工程である。本発明の炭素質材料は、その特性上、特に電気化学デバイスなどに用いる非水系分極性電極の材料として適しており、そのような用途に適する粒径として、平均粒子径が好ましくは４～１５μｍ、より好ましくは５～１０μｍとなるよう炭素質材料を粉砕することが好ましい。 [Crushing process]
In the present invention, the method for producing a carbonaceous material may include a pulverization step. The pulverization step is a step for controlling the shape and particle size of the finally obtained carbonaceous material to a desired shape and particle size. Due to its characteristics, the carbonaceous material of the present invention is particularly suitable as a material for a non-aqueous polar electrode used in an electrochemical device or the like, and the average particle size is preferably 4 to 15 μm as a particle size suitable for such applications. , More preferably, the carbonaceous material is ground to a size of 5 to 10 μm.
　粉砕に用いる粉砕機は、特に限定されるものではなく、例えば、コーンクラッシャー、ダブルロールクラッシャー、ディスククラッシャー、ロータリークラッシャー、ボールミル、遠心ロールミル、リングロールミル、遠心ボールミル、ジェットミルなどの公知の粉砕機を、単独でまたは組み合わせて用いることができる。 The crusher used for crushing is not particularly limited, and for example, a known crusher such as a cone crusher, a double roll crusher, a disc crusher, a rotary crusher, a ball mill, a centrifugal roll mill, a ring roll mill, a centrifugal ball mill, or a jet mill can be used. , Can be used alone or in combination.
［分級工程］
　本発明において、炭素質材料の製造方法は分級工程を含んでもよい。例えば、粒子径が１μｍ以下の粒子を除くことにより狭い粒度分布幅を有する炭素質材料粒子を得ることが可能となる。このような微粒子除去により、電極構成時のバインダー量を少なくすることが可能となる。分級方法は、特に制限されないが、例えば篩を用いた分級、湿式分級、乾式分級を挙げることができる。湿式分級機としては、例えば重力分級、慣性分級、水力分級、遠心分級等の原理を利用した分級機を挙げることができる。乾式分級機としては、沈降分級、機械的分級、遠心分級等の原理を利用した分級機を挙げることができる。経済性の観点から、乾式分級装置を用いることが好ましい。 [Classification process]
In the present invention, the method for producing a carbonaceous material may include a classification step. For example, it is possible to obtain carbonaceous material particles having a narrow particle size distribution width by excluding particles having a particle diameter of 1 μm or less. By removing such fine particles, it is possible to reduce the amount of binder in the electrode configuration. The classification method is not particularly limited, and examples thereof include classification using a sieve, wet classification, and dry classification. Examples of the wet classifier include classifiers that utilize principles such as gravity classification, inertial classification, hydraulic classification, and centrifugal classification. Examples of the dry classifier include classifiers that utilize principles such as sedimentation classification, mechanical classification, and centrifugal classification. From the viewpoint of economy, it is preferable to use a dry classification device.
　粉砕と分級とを、１つの装置を用いて実施することもできる。例えば、乾式の分級機能を備えたジェットミルを用いて、粉砕および分級を実施することができる。更に、粉砕機と分級機とが独立した装置を用いることもできる。この場合、粉砕と分級とを連続して行うこともできるが、粉砕と分級とを不連続に行うこともできる。 It is also possible to carry out crushing and classification using one device. For example, pulverization and classification can be carried out using a jet mill having a dry classification function. Further, a device in which the crusher and the classifier are independent can be used. In this case, crushing and classification can be performed continuously, but crushing and classification can also be performed discontinuously.
　本発明の炭素質材料は、各種電気化学デバイスの電極材等として好適に用いることができる。したがって、本発明の一実施態様においては、本発明の炭素質材料を用いて電気化学デバイス用電極活物質および、その製造方法を提供することができ、また、該電極活物質または該電極活物質の製造方法により得られる電極活物質を用いて電気化学デバイス用電極およびその製造方法を提供することができ、さらに、該電極または該電極の製造方法により得られる電極を用いて電気化学デバイスおよびその製造方法を提供することができる。 The carbonaceous material of the present invention can be suitably used as an electrode material or the like for various electrochemical devices. Therefore, in one embodiment of the present invention, the electrode active material for an electrochemical device and a method for producing the electrode active material can be provided by using the carbonaceous material of the present invention, and the electrode active material or the electrode active material can be provided. An electrode for an electrochemical device and a method for manufacturing the same can be provided by using the electrode active material obtained by the manufacturing method of the above, and further, the electrode or the electrode obtained by the manufacturing method of the electrode is used for the electrochemical device and the method thereof. A manufacturing method can be provided.
　前記電気化学デバイス用電極活物質は、本発明の炭素質材料を用いることにより製造できる。その製造工程としては、例えば、原料となる本発明の炭素質材料と、導電性付与剤、バインダー、溶剤等の成分を混錬する工程、混錬物を塗工・乾燥する工程等の電極材料の製造工程として従来当該分野において一般的な製造工程を含むことができる。また、前記電気化学デバイス用電極は、前記電極活物質を用いることにより製造でき、その製造工程としては、例えば、原料となる前記電極活物質に溶剤を添加してペーストを調製する工程、前記ペーストをアルミ箔等の集電板に塗布した後、溶媒を乾燥除去する工程、前記ペーストを金型に入れプレス成形する工程を含むことができる。 The electrode active material for an electrochemical device can be produced by using the carbonaceous material of the present invention. The manufacturing process includes, for example, an electrode material such as a step of kneading a carbonaceous material of the present invention as a raw material with components such as a conductivity-imparting agent, a binder, and a solvent, and a step of coating and drying the kneaded product. As the manufacturing process of the above, a manufacturing process generally used in the art can be included. Further, the electrode for an electrochemical device can be manufactured by using the electrode active material, and the manufacturing process thereof includes, for example, a step of adding a solvent to the electrode active material as a raw material to prepare a paste, and the paste. Can be included in a step of drying and removing the solvent after applying the above to a current collector plate such as an aluminum foil, and a step of putting the paste in a mold and press-molding.
　この電極に使用される導電性付与剤としては、例えば、アセチレンブラック、ケッチェンブラック等を用いることができる。バインダーとしては、例えば、ポリテトラフルオロエチレン、ポリフッ化ビニリデン等のフッ素系高分子化合物や、カルボキシメチルセルロース、スチレン－ブタジエンゴム、石油ピッチ、フェノール樹脂等を用いることができる。また、溶剤としては、例えば、水、メタノール、エタノールなどのアルコール類、ヘキサン、ヘプタンなどの飽和炭化水素、トルエン、キシレン、メシチレンなどの芳香族炭化水素、アセトン、エチルメチルケトンなどのケトン類、酢酸メチル、酢酸エチルなどのエステル類、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジエチルホルムアミドなどのアミド類、Ｎ－メチルピロリドン、Ｎ－エチルピロリドンなどの環状アミド類等を用いることができる。 As the conductivity-imparting agent used for this electrode, for example, acetylene black, ketjen black and the like can be used. As the binder, for example, a fluorine-based polymer compound such as polytetrafluoroethylene or polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubber, petroleum pitch, phenol resin and the like can be used. Examples of the solvent include water, alcohols such as methanol and ethanol, saturated hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene, xylene and mesityrene, ketones such as acetone and ethylmethylketone, and acetic acid. Esters such as methyl and ethyl acetate, amides such as N, N-dimethylformamide and N, N-diethylformamide, cyclic amides such as N-methylpyrrolidone and N-ethylpyrrolidone and the like can be used.
　本発明の電気化学デバイスは、前記電極を用いることにより製造できる。電気化学デバイスは、一般に、電極、電解液、およびセパレータを主要構成とし、一対の電極間にセパレータを配置した構造となっている。電解液としては、例えば、プロピレンカーボネート、エチレンカーボネート、メチルエチルカーボネート、アセトニトリル等の有機溶剤にアミジン塩を溶解した電解液、過塩素酸の４級アンモニウム塩を溶解した電解液、４級アンモニウムやリチウム等のアルカリ金属の四フッ化ホウ素塩や六フッ化リン塩を溶解した電解液、４級ホスホニウム塩を溶解した電解液等が挙げられる。また、セパレータとしては、例えば、セルロース、ガラス繊維、または、ポリエチレンやポリプロピレン等のポリオレフィンを主成分とした不織布、クロス、微孔フィルムが挙げられる。電気化学デバイスは、例えば、これらの主要な構成を、従来当該分野において一般的な方法により配置することにより製造することができる。 The electrochemical device of the present invention can be manufactured by using the electrode. In general, an electrochemical device has an electrode, an electrolytic solution, and a separator as a main configuration, and has a structure in which a separator is arranged between a pair of electrodes. Examples of the electrolytic solution include an electrolytic solution in which an amidine salt is dissolved in an organic solvent such as propylene carbonate, ethylene carbonate, methyl ethyl carbonate, and acetonitrile, an electrolytic solution in which a quaternary ammonium salt of perchloric acid is dissolved, and quaternary ammonium and lithium. Examples thereof include an electrolytic solution in which a boron tetrafluoride salt and a phosphorus hexafluoride salt of an alkali metal are dissolved, and an electrolytic solution in which a quaternary phosphonium salt is dissolved. Examples of the separator include non-woven fabrics, cloths, and micropore films containing cellulose, glass fibers, or polyolefins such as polyethylene and polypropylene as main components. Electrochemical devices can be manufactured, for example, by arranging these major configurations in a manner conventionally common in the art.
　本発明の炭素質材料を用いて製造される電気化学デバイスは、炭素質材料の比表面積や細孔収縮の低下を伴う熱処理を行うことなく、高い電気伝導率を有し、且つ、炭素質材料表面に存在する表面官能基および骨格内酸素量の量が低減されているため、初期静電容量を高くすることができ、電解液との反応性が低く、充放電時のガス発生抑制効果が高く、長期使用による静電容量の低下を抑制でき、耐久性に優れ、さらに低温下であっても優れた性能を維持することができる。 The electrochemical device manufactured using the carbonaceous material of the present invention has high electrical conductivity and is a carbonaceous material without performing heat treatment accompanied by a decrease in the specific surface area and pore shrinkage of the carbonaceous material. Since the amount of surface functional groups and oxygen in the skeleton present on the surface is reduced, the initial capacitance can be increased, the reactivity with the electrolytic solution is low, and the effect of suppressing gas generation during charging and discharging is achieved. It is high, can suppress the decrease in capacitance due to long-term use, has excellent durability, and can maintain excellent performance even at low temperatures.
　以下に実施例に基づいて本発明をより詳細に述べるが、以下の実施例は、本発明を限定するものではない。実施例および比較例における各物性値は以下の方法により測定した。 The present invention will be described in more detail below based on the examples, but the following examples do not limit the present invention. Each physical property value in Examples and Comparative Examples was measured by the following method.
［比表面積測定］
　マイクロトラック・ベル（株）製のＢＥＬＳＯＲＰ－ｍｉｎｉを使用し、試料となる炭素質材料を窒素気流下（窒素流量：５０ｍＬ／分）にて３００℃で３時間加熱した後、７７．４Ｋにおける炭素質材料の窒素吸着等温線を測定した。得られた吸着等温線からＢＥＴ式により多点法による解析を行い、得られた曲線の相対圧Ｐ／Ｐ０＝０．０１～０．１の領域での直線から比表面積を算出した。 [Specific surface area measurement]
Using BELSORP-mini manufactured by Microtrac Bell Co., Ltd., the sample carbonaceous material was heated at 300 ° C. for 3 hours under a nitrogen stream (nitrogen flow rate: 50 mL / min), and then carbon at 77.4 K. The nitrogen adsorption isotherm of the quality material was measured. The obtained adsorption isotherm was analyzed by the multipoint method by the BET formula, and the specific surface area was calculated from the straight line in the region of the relative pressure P / P 0 = 0.01 to 0.1 of the obtained curve.
［全細孔容積・平均細孔径］
　マイクロトラック・ベル（株）製のＢＥＬＳＯＲＰ－ｍｉｎｉを使用し、試料となる炭素質材料を窒素気流下（窒素流量：５０ｍＬ／分）にて３００℃で３時間加熱した後、７７．４Ｋにおける炭素質材料の窒素吸着等温線を測定した。得られた吸着等温線における相対圧Ｐ／Ｐ０＝０．９９における窒素吸着量から求めた全細孔容積を用い、平均細孔径に関しては全細孔容積および先に記載したＢＥＴ法から求めた比表面積より、下記式に基づいて算出した。 [Total pore volume / average pore diameter]
Using BELSORP-mini manufactured by Microtrac Bell Co., Ltd., the sample carbonaceous material was heated at 300 ° C. for 3 hours under a nitrogen stream (nitrogen flow rate: 50 mL / min), and then carbon at 77.4 K. The nitrogen adsorption isotherm of the quality material was measured. The total pore volume determined from the nitrogen adsorption amount at the relative pressure P / P 0 = 0.99 on the obtained adsorption isotherm was used, and the average pore diameter was determined from the total pore volume and the BET method described above. It was calculated from the specific surface area based on the following formula.
平均細孔径（ｎｍ）＝全細孔容積（ｃｍ３／ｇ）／比表面積（ｍ２／ｇ）×４０００ Average pore diameter (nm) = total pore volume (cm 3 / g) / specific surface area (m 2 / g) x 4000
［酸素含量、水素含量の測定方法、Ｏ／Ｈ、比表面積あたりのＯ／Ｈ］
　株式会社堀場製作所製、ＥＭＧＡ－９３０を用いて行った。当該装置の検出方法は、酸素：不活性ガス融解－非分散型赤外吸収法（ＮＤＩＲ）、水素：不活性ガス融解－非分散型赤外吸収法（ＮＤＩＲ）であり、校正は、（酸素）Ｎｉカプセル、ＴｉＨ２（Ｈ標準試料）ＳＳ－３（Ｏ標準試料）で行い、前処理として２２０℃、約１０分で乾燥処理を実施した試料５ｍｇをＮｉカプセルに取り、上記装置内で３０秒脱ガスした後に測定した。試験は３検体で分析し、平均値を分析値とした。得られた値からＯ／Ｈを求め、その値を上記で得られたＢＥＴ比表面積で除することにより、比表面積あたりのＯ／Ｈを求めた。 [Measurement method of oxygen content and hydrogen content, O / H, O / H per specific surface area]
This was performed using EMGA-930 manufactured by HORIBA, Ltd. The detection method of the device is oxygen: inert gas melting-non-dispersion infrared absorption method (NDIR), hydrogen: inert gas melting-non-dispersion infrared absorption method (NDIR), and the calibration is (oxygen). ) Ni capsules, TiH 2 (H standard sample) SS-3 (O standard sample), and dried at 220 ° C. for about 10 minutes as a pretreatment. Take 5 mg of the sample into Ni capsules and use 30 in the above device. Measured after degassing for seconds. The test was analyzed with 3 samples, and the average value was used as the analysis value. The O / H was determined from the obtained value, and the value was divided by the BET specific surface area obtained above to obtain the O / H per specific surface area.
［導電率の測定方法］
　三菱化学アナリテック社製、粉体抵抗測定ユニット「ＭＣＰ－ＰＤ５１」を使用し、賦活処理後酸洗浄前の炭素質材料前駆体および炭素質材料の導電率を測定した。導電率の測定は、平均粒子径が５．０μｍ～６．０μｍの炭素質材料前駆体または炭素質材料を用い、荷重を１２ｋＮかけた際の炭素質材料前駆体ペレットまたは炭素質材料ペレットの厚みが３．５～４．５ｍｍとなる量の材料を使用し、荷重を１２ｋＮかけた状態での炭素質材料前駆体ペレットおよび炭素質材料ペレットの導電率を測定した。 [Measurement method of conductivity]
Using a powder resistance measuring unit "MCP-PD51" manufactured by Mitsubishi Chemical Analytech Co., Ltd., the conductivity of the carbonaceous material precursor and the carbonaceous material after the activation treatment and before the acid cleaning was measured. The conductivity is measured using a carbonaceous material precursor or carbonaceous material having an average particle size of 5.0 μm to 6.0 μm, and the thickness of the carbonaceous material precursor pellet or carbonaceous material pellet when a load of 12 kN is applied. The conductivity of the carbonaceous material precursor pellet and the carbonaceous material pellet was measured under a load of 12 kN using a material having an amount of 3.5 to 4.5 mm.
［平均粒子径測定］
　炭素質材料の粒径はレーザー回折測定法により測定した。すなわち、測定対象である炭素質材料を界面活性剤と共にイオン交換水中に入れ、ＥＭＥＲＳＯＮ社製のＢＲＡＮＳＯＮＩＣ　Ｍ２８００－Ｊを用いて超音波振動を与え均一分散液を作製し、米国マイクロトラック社製のＭｉｃｒｏｔｒａｃ　ＭＴ３０００を用いて吸収法にて測定した。また、均一分散を目的に使用される界面活性剤には、株式会社花王製の「Ｔｒｉｔｏｎ－Ｘ　１００」を用いた。界面活性剤は、均一分散させることが可能であり、測定に影響を与える気泡等が発生しない適当量を添加した。 [Measurement of average particle size]
The particle size of the carbonaceous material was measured by a laser diffraction measurement method. That is, the carbonaceous material to be measured was put into ion-exchanged water together with a surfactant, and ultrasonic vibration was applied using BRANSONIC M2800-J manufactured by EMERSON to prepare a uniform dispersion liquid, and Microtrac manufactured by Microtrack, USA. It was measured by the absorption method using MT3000. Further, as the surfactant used for the purpose of uniform dispersion, "Triton-X 100" manufactured by Kao Corporation was used. The surfactant was added in an appropriate amount which can be uniformly dispersed and does not generate bubbles or the like which affect the measurement.
　＜実施例１＞
　フィリピン産ココナツのヤシ殻を原料とするチャー（ＢＥＴ比表面積：３７０ｍ２/ｇ）に対し、プロパン燃焼ガスと水蒸気（水蒸気分圧：１８％）を用いて、９５０℃で賦活する時の反応速度が毎分当たり１．４m2／ｇで下記比表面積となるまで一次賦活を行い、ＢＥＴ比表面積が１９０２ｍ２／ｇ、平均細孔径１．９３ｎｍの一次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、純度９９．９９％の窒素を流通容器内に流通し、排出、また、排出する際、排出時に同伴させる燃焼ガスを積極的に窒素ガスで置換した後、窒素ガス雰囲気下（容器内における一次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量を０．５Ｌ／Ｋｇ以下の状態）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１９１９ｍ２／ｇ、平均細孔径１．９３ｎｍの炭素質材料（１）を得た。炭素質材料（１）の各種物性を測定した。その結果を表１に示す。 <Example 1>
Reaction rate when activating at 950 ° C using propane combustion gas and steam (partial pressure of steam: 18%) with char (BET specific surface area: 370 m 2 / g) made from coconut husks produced in the Philippines. The primary activation was carried out at 1.4 m 2 / g per minute until the following specific surface area was obtained, to obtain a primary activated granular carbonaceous material precursor having a BET specific surface area of 1902 m 2 / g and an average pore diameter of 1.93 nm. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container). The total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (1) having a BET specific surface area of 1919 m 2 / g and an average pore diameter of 1.93 nm. Various physical properties of the carbonaceous material (1) were measured. The results are shown in Table 1.
　＜比較例１＞
　フィリピン産ココナツのヤシ殻を原料とするチャー（ＢＥＴ比表面積：３７０ｍ２/ｇ）に対し、プロパン燃焼ガスと水蒸気（水蒸気分圧：１８％）を用いて、９００℃賦活する時の反応速度が毎分当たり１．３m2／ｇで下記比表面積となるまで一次賦活を行い、ＢＥＴ比表面積が１１８５ｍ２／ｇの一次賦活粒状炭素質材料前駆体を得た。その後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、残留した酸を除去するため、イオン交換水で十分に水洗し脱塩した。脱塩後、１２０℃で乾燥して、一次洗浄粒状炭素質材料前駆体を得た。この粒状炭素質材料前駆体をさらに、プロパン燃焼ガスと水蒸気（水蒸気分圧１５％）を用い、９００℃で賦活する時の反応速度が毎分当たり３．６m2／ｇで下記比表面積となるまで二次賦活を行い、ＢＥＴ比表面積１８５９ｍ２／ｇ、平均細孔径２．００ｎｍの二次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、大気で満たされた容器内に同伴される燃焼ガスと共に排出し、同雰囲気内（容器内の二次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量が１．５Ｌ／Ｋｇ以上）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１８７１ｍ２／ｇ、平均細孔径２．００ｎｍの炭素質材料（２）を得た。炭素質材料（２）の各種物性を測定した。その結果を表１に示す。 <Comparative example 1>
The reaction rate when activating at 900 ° C using propane combustion gas and steam (partial pressure of steam: 18%) with respect to char (BET specific surface area: 370 m 2 / g) made from coconut husks produced in the Philippines performs primary activation per minute per 1.3 m 2 / g until the following specific surface, BET specific surface area was obtained primary activation particulate carbonaceous material precursor of 1185m 2 / g. Then, after pickling with hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water) at a temperature of 70 ° C. for 30 minutes, the acid was thoroughly washed with ion-exchanged water to remove the residual acid. Salted. After desalting, it was dried at 120 ° C. to obtain a primary washing granular carbonaceous material precursor. When this granular carbonaceous material precursor is further activated at 900 ° C. using propane combustion gas and water vapor (partial pressure of water vapor 15%), the reaction rate is 3.6 m 2 / g per minute, which gives the following specific surface area. The secondary activation was carried out to obtain a secondary activated granular carbonaceous material precursor having a BET specific surface area of 1859 m 2 / g and an average pore diameter of 2.00 nm. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, the gas is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the secondary activated granular carbonaceous material precursor in the container is 1.5 L / L. The mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (2) having a BET specific surface area of 1871 m 2 / g and an average pore diameter of 2.00 nm. Various physical properties of the carbonaceous material (2) were measured. The results are shown in Table 1.
　＜比較例２＞
　フィリピン産ココナツのヤシ殻を原料とするチャー（ＢＥＴ比表面積：３７０ｍ２/ｇ）に対し、プロパン燃焼ガスと水蒸気（水蒸気分圧：１８％）を用いて、９００℃で賦活する時の反応速度が毎分当たり１．２m2／ｇで下記比表面積となるまで一次賦活を行い、ＢＥＴ比表面積が１９２４ｍ２／ｇ、平均細孔径１．９３ｎｍの一次賦活粒状炭素質材料前駆体を得た。その後、炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、処理を実施した。処理終了後、大気で満たされた容器内に同伴される燃焼ガスと共に排出し、同雰囲気内（容器内の一次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量が１．５Ｌ／Ｋｇ以上）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１９３５ｍ２／ｇ、平均細孔径１．９４ｎｍの炭素質材料（３）を得た。得られた炭素質材料（３）の各種物性を測定した。その結果を表１に示す。 <Comparative example 2>
Reaction rate when activating at 900 ° C with propane combustion gas and steam (partial pressure of steam: 18%) for char (BET specific surface area: 370 m 2 / g) made from coconut husks produced in the Philippines. The primary activation was carried out at 1.2 m 2 / g per minute until the following specific surface area was obtained, to obtain a primary activated granular carbonaceous material precursor having a BET specific surface area of 1924 m 2 / g and an average pore diameter of 1.93 nm. Then, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then hydrochloric acid (concentration: 0.5 specified, diluent: ion-exchanged water) was used at a temperature of 70 ° C. After pickling for 30 minutes, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, the treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, it is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor in the container is 1.5 L / Kg. The above) was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) to obtain a carbonaceous material.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (3) having a BET specific surface area of 1935 m 2 / g and an average pore diameter of 1.94 nm. Various physical properties of the obtained carbonaceous material (3) were measured. The results are shown in Table 1.
　＜比較例３＞
　比較例２と同様にして、炭素質材料を得た。次に、得られた炭素質材料を窒素雰囲気下、２４℃／分の昇温速度で６００℃まで、１２℃／分の昇温速度で９００℃まで、１．６７℃／分の昇温速度で１１００℃まで段階的に昇温した後、１１００℃で６０分保持することにより熱処理を行った。その後、炉内温度が７０℃以下になるまで用いたガス（窒素）の雰囲気下で自然冷却し（冷却時間約３．０時間）、熱処理炭素質材料を得た。この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１７８２ｍ２／ｇ、平均細孔径１．９６ｎｍの炭素質材料（４）を得た。炭素質材料（４）の各種物性を測定した。その結果を表１に示す。 <Comparative example 3>
A carbonaceous material was obtained in the same manner as in Comparative Example 2. Next, the obtained carbonaceous material was heated to 600 ° C. at a heating rate of 24 ° C./min, to 900 ° C. at a heating rate of 12 ° C./min, and at a heating rate of 1.67 ° C./min under a nitrogen atmosphere. After stepwise raising the temperature to 1100 ° C., heat treatment was performed by holding at 1100 ° C. for 60 minutes. Then, it was naturally cooled in the atmosphere of the gas (nitrogen) used until the temperature in the furnace became 70 ° C. or lower (cooling time was about 3.0 hours) to obtain a heat-treated carbonaceous material. This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (4) having a BET specific surface area of 1782 m 2 / g and an average pore diameter of 1.96 nm. Various physical properties of the carbonaceous material (4) were measured. The results are shown in Table 1.
　＜比較例４＞
　比較例２と同様にして、炭素質材料を得た。次に、得られた炭素質材料を窒素雰囲気下、２４℃／分の昇温速度で６００℃まで、１２℃／分の昇温速度で９００℃まで、１．６７℃／分の昇温速度で１２００℃まで段階的に昇温した後、１２００℃で６０分保持することにより熱処理を行った。その後、炉内温度が７０℃以下になるまで用いたガス（窒素）の雰囲気下で自然冷却し（冷却時間約３．０時間）、熱処理炭素質材料を得た。この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１６９８ｍ２／ｇ、平均細孔径１．９７ｎｍの炭素質材料（５）を得た。炭素質材料（５）の各種物性を測定した。その結果を表１に示す。 <Comparative example 4>
A carbonaceous material was obtained in the same manner as in Comparative Example 2. Next, the obtained carbonaceous material was subjected to a heating rate of 24 ° C./min to 600 ° C., a heating rate of 12 ° C./min to 900 ° C., and a heating rate of 1.67 ° C./min under a nitrogen atmosphere. After stepwise raising the temperature to 1200 ° C., heat treatment was performed by holding at 1200 ° C. for 60 minutes. Then, it was naturally cooled in the atmosphere of the gas (nitrogen) used until the temperature in the furnace became 70 ° C. or lower (cooling time was about 3.0 hours) to obtain a heat-treated carbonaceous material. This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (5) having a BET specific surface area of 1698 m 2 / g and an average pore diameter of 1.97 nm. Various physical properties of the carbonaceous material (5) were measured. The results are shown in Table 1.
＜実施例２＞
　実施例１と同様にして、ＢＥＴ比表面積が１６８８ｍ２／ｇ、平均細孔径１．８１ｎｍの一次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、純度９９．９９％の窒素を流通容器内に流通し、排出、また、排出する際、排出時に同伴させる燃焼ガスを積極的に窒素ガスで置換した後、窒素ガス雰囲気下（容器内における一次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量を０．５Ｌ／Ｋｇ以下の状態）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１７０１ｍ２／ｇ、平均細孔径１．８１ｎｍの炭素質材料（６）を得た。炭素質材料（６）の各種物性を測定した。その結果を表１に示す。 <Example 2>
In the same manner as in Example 1, a primary activated granular carbonaceous material precursor having a BET specific surface area of 1688 m 2 / g and an average pore diameter of 1.81 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container). The total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (6) having a BET specific surface area of 1701 m 2 / g and an average pore diameter of 1.81 nm. Various physical properties of the carbonaceous material (6) were measured. The results are shown in Table 1.
＜実施例３＞
　実施例１と同様にして、ＢＥＴ比表面積が２３７２ｍ２／ｇ、平均細孔径２．２５ｎｍの一次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、純度９９．９９％の窒素を流通容器内に流通し、排出、また、排出する際、排出時に同伴させる燃焼ガスを積極的に窒素ガスで置換した後、窒素ガス雰囲気下（容器内における一次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量を０．５Ｌ／Ｋｇ以下の状態）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積２３８２ｍ２／ｇ、平均細孔径２．２５ｎｍの炭素質材料（７）を得た。炭素質材料（７）の各種物性を測定した。その結果を表１に示す。 <Example 3>
In the same manner as in Example 1, a primary activated granular carbonaceous material precursor having a BET specific surface area of 2372 m 2 / g and an average pore diameter of 2.25 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container). The total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (7) having a BET specific surface area of 2382 m 2 / g and an average pore diameter of 2.25 nm. Various physical properties of the carbonaceous material (7) were measured. The results are shown in Table 1.
＜比較例５＞
　比較例１と同様にして、ＢＥＴ比表面積が１６００ｍ２／ｇ、平均細孔径２．０４ｎｍの二次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、大気で満たされた容器内に同伴される燃焼ガスと共に排出し、同雰囲気内（容器内の二次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量が１．５Ｌ／Ｋｇ以上）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１６１５ｍ２／ｇ、平均細孔径２．０４ｎｍの炭素質材料（８）を得た。炭素質材料（８）の各種物性を測定した。その結果を表１に示す。 <Comparative example 5>
In the same manner as in Comparative Example 1, a secondary activated granular carbonaceous material precursor having a BET specific surface area of 1600 m 2 / g and an average pore diameter of 2.04 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, the gas is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the secondary activated granular carbonaceous material precursor in the container is 1.5 L / L. The mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (8) having a BET specific surface area of 1615 m 2 / g and an average pore diameter of 2.04 nm. Various physical properties of the carbonaceous material (8) were measured. The results are shown in Table 1.
＜比較例６＞
　比較例１と同様にして、ＢＥＴ比表面積が１６００ｍ２／ｇ、平均細孔径２．０１ｎｍの二次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、純度９９．９９％の窒素を流通容器内に流通し、排出、また、排出する際、排出時に同伴させる燃焼ガスを積極的に窒素ガスで置換した後、窒素ガス雰囲気下（容器内における一次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量を０．５Ｌ／Ｋｇ以下の状態）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１６１５ｍ２／ｇ、平均細孔径２．０１ｎｍの炭素質材料（９）を得た。炭素質材料（９）の各種物性を測定した。その結果を表１に示す。 <Comparative Example 6>
In the same manner as in Comparative Example 1, a secondary activated granular carbonaceous material precursor having a BET specific surface area of 1600 m 2 / g and an average pore diameter of 2.01 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, nitrogen having a purity of 99.99% is circulated in the distribution container and discharged, and when discharged, the combustion gas accompanied at the time of discharge is positively replaced with nitrogen gas, and then in a nitrogen gas atmosphere (container). The total amount of oxidizing gas per mass of the primary activated granular carbonaceous material precursor was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at 0.5 L / Kg or less) to obtain a carbonaceous material. It was.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (9) having a BET specific surface area of 1615 m 2 / g and an average pore diameter of 2.01 nm. Various physical properties of the carbonaceous material (9) were measured. The results are shown in Table 1.
　＜比較例７＞
　比較例５と同様にして、炭素質材料を得た。次に、得られた炭素質材料を窒素雰囲気下、２４℃／分の昇温速度で６００℃まで、１２℃／分の昇温速度で９００℃まで、１．６７℃／分の昇温速度で１１００℃まで段階的に昇温した後、１１００℃で６０分保持することにより熱処理を行った。その後、炉内温度が７０℃以下になるまで用いたガス（窒素）の雰囲気下で自然冷却し（冷却時間約３．０時間）、熱処理炭素質材料を得た。この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１４８６ｍ２／ｇ、平均細孔径２．０２ｎｍの炭素質材料（１０）を得た。炭素質材料（１０）の各種物性を測定した。その結果を表１に示す。 <Comparative Example 7>
A carbonaceous material was obtained in the same manner as in Comparative Example 5. Next, the obtained carbonaceous material was heated to 600 ° C. at a heating rate of 24 ° C./min, to 900 ° C. at a heating rate of 12 ° C./min, and at a heating rate of 1.67 ° C./min under a nitrogen atmosphere. After stepwise raising the temperature to 1100 ° C., heat treatment was performed by holding at 1100 ° C. for 60 minutes. Then, it was naturally cooled in the atmosphere of the gas (nitrogen) used until the temperature in the furnace became 70 ° C. or lower (cooling time was about 3.0 hours) to obtain a heat-treated carbonaceous material. This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (10) having a BET specific surface area of 1486 m 2 / g and an average pore diameter of 2.02 nm. Various physical properties of the carbonaceous material (10) were measured. The results are shown in Table 1.
　＜比較例８＞
　比較例５と同様にして、炭素質材料を得た。次に、得られた炭素質材料を窒素雰囲気下、２４℃／分の昇温速度で６００℃まで、１２℃／分の昇温速度で９００℃まで、１．６７℃／分の昇温速度で１１００℃まで段階的に昇温した後、１２００℃で６０分保持することにより熱処理を行った。その後、炉内温度が７０℃以下になるまで用いたガス（窒素）の雰囲気下で自然冷却し（冷却時間約３．０時間）、熱処理炭素質材料を得た。この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積１４４８ｍ２／ｇ、平均細孔径２．０３ｎｍの炭素質材料（１１）を得た。炭素質材料（１１）の各種物性を測定した。その結果を表１に示す。 <Comparative Example 8>
A carbonaceous material was obtained in the same manner as in Comparative Example 5. Next, the obtained carbonaceous material was subjected to a heating rate of 24 ° C./min to 600 ° C., a heating rate of 12 ° C./min to 900 ° C., and a heating rate of 1.67 ° C./min under a nitrogen atmosphere. After stepwise raising the temperature to 1100 ° C., heat treatment was performed by holding at 1200 ° C. for 60 minutes. Then, it was naturally cooled in the atmosphere of the gas (nitrogen) used until the temperature in the furnace became 70 ° C. or lower (cooling time was about 3.0 hours) to obtain a heat-treated carbonaceous material. This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (11) having a BET specific surface area of 1448 m 2 / g and an average pore diameter of 2.03 nm. Various physical properties of the carbonaceous material (11) were measured. The results are shown in Table 1.
＜比較例９＞
　比較例１と同様にして、ＢＥＴ比表面積が２２３６ｍ２／ｇ、平均細孔径２．２３ｎｍの二次賦活粒状炭素質材料前駆体を得た。その後炭素質材料前駆体としての粉体導電率を測定するために一部をサンプル採取した後、塩酸（濃度：０．５規定、希釈液：イオン交換水）を用いて、温度７０℃で３０分酸洗した後、イオン交換水で水洗し乾燥した。その後、細孔内に残留した塩素分を除去するため、プロパン燃焼ガス雰囲気７００℃にて、脱酸処理を実施した。処理終了後、大気で満たされた容器内に同伴される燃焼ガスと共に排出し、同雰囲気内（容器内の二次賦活粒状炭素質材料前駆体質量あたりの酸化性ガスの総量が１．５Ｌ／Ｋｇ以上）で２００℃以下まで冷却し（冷却時間約１．０時間）、炭素質材料を得た。
　この炭素質材料を平均粒子径が６μｍになるように微粉砕し、ＢＥＴ比表面積２２４３ｍ２／ｇ、平均細孔径２．２３ｎｍの炭素質材料（１２）を得た。炭素質材料（１２）の各種物性を測定した。その結果を表１に示す。 <Comparative Example 9>
In the same manner as in Comparative Example 1, a secondary activated granular carbonaceous material precursor having a BET specific surface area of 2236 m 2 / g and an average pore diameter of 2.23 nm was obtained. After that, a part of the sample was taken to measure the powder conductivity as a carbonaceous material precursor, and then using hydrochloric acid (concentration: 0.5 specification, diluent: ion-exchanged water), 30 ° C. at a temperature of 70 ° C. After partial pickling, it was washed with ion-exchanged water and dried. Then, in order to remove the chlorine content remaining in the pores, a deoxidizing treatment was carried out in a propane combustion gas atmosphere of 700 ° C. After the treatment is completed, the gas is discharged together with the combustion gas accompanying the container filled with air, and the total amount of oxidizing gas per mass of the secondary activated granular carbonaceous material precursor in the container is 1.5 L / L. The mixture was cooled to 200 ° C. or lower (cooling time: about 1.0 hour) at (Kg or more) to obtain a carbonaceous material.
This carbonaceous material was finely pulverized so that the average particle size was 6 μm to obtain a carbonaceous material (12) having a BET specific surface area of 2243 m 2 / g and an average pore diameter of 2.23 nm. Various physical properties of the carbonaceous material (12) were measured. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
［測定電極セル作製］
　実施例１～３および比較例１～９で調製した炭素質材料を用いて、以下の電極の作製方法に従い、電極組成物を得て、これを用いて分極性電極を作製した。さらに、分極性電極を用いて測定電極セル（電気化学デバイス）を作製した。得られた測定電極セルを用いて、下記方法に従って、静電容量測定、耐久性試験およびガス発生量の測定を行った。各測定結果を表２に示す。 [Measurement electrode cell fabrication]
Using the carbonaceous materials prepared in Examples 1 to 3 and Comparative Examples 1 to 9, an electrode composition was obtained according to the following electrode preparation method, and a polarizable electrode was prepared using the electrode composition. Further, a measuring electrode cell (electrochemical device) was prepared using the polarizable electrode. Using the obtained measurement electrode cell, capacitance measurement, durability test and gas generation amount measurement were performed according to the following methods. The measurement results are shown in Table 2.
　電極構成部材として、実施例１～３および比較例１～９で調製した炭素質材料、導電助材およびバインダーは、事前に１２０℃、減圧（０．１ＫＰａ以下）の雰囲気にて１６時間以上減圧乾燥を行い使用した。
　前記炭素質材料、導電助材およびバインダーを、（炭素質材料の質量）：（導電助材の質量）：（バインダーの質量）の比が８１：９：１０となるように秤量し、混錬した。上記導電助材としては、電気化学工業（株）製の導電性カーボンブラック「デンカブラック粒状」を使用し、上記バインダーとしては、三井・デュポン（株）製のポリテトラフルオロエチレン「６Ｊ」を使用した。混錬後、さらに均一化を図る為、１ｍｍ角以下のフレーク状にカットし、コイン成形機にて４００Ｋｇ／ｃｍ２の圧力を与え、コイン状の二次成形物を得た。得られた二次成形物をロールプレス機により１６０μｍ±５％の厚みのシート状に成形した後、所定の大きさ（３０ｍｍ×３０ｍｍ）に切り出し、図１に示すような電極組成物１を作製した。得られた電極組成物１を１２０℃、減圧雰囲気下で１６時間以上乾燥した後、質量、シート厚みおよび寸法を計測し、以下の測定に用いた。 As the electrode constituent members, the carbonaceous materials, conductive auxiliary materials and binders prepared in Examples 1 to 3 and Comparative Examples 1 to 9 were decompressed in advance at 120 ° C. in an atmosphere of reduced pressure (0.1 KPa or less) for 16 hours or more. It was dried and used.
The carbonaceous material, the conductive auxiliary material and the binder are weighed so that the ratio of (mass of carbonaceous material): (mass of conductive auxiliary material): (mass of binder) is 81: 9: 10 and kneaded. did. As the conductive auxiliary material, conductive carbon black "Denka Black Granule" manufactured by Denki Kagaku Kogyo Co., Ltd. is used, and as the binder, polytetrafluoroethylene "6J" manufactured by Mitsui DuPont Co., Ltd. is used. did. After kneading, in order to further make it uniform, it was cut into flakes of 1 mm square or less, and a pressure of 400 kg / cm 2 was applied with a coin molding machine to obtain a coin-shaped secondary molded product. The obtained secondary molded product is formed into a sheet having a thickness of 160 μm ± 5% by a roll press machine, and then cut into a predetermined size (30 mm × 30 mm) to prepare an electrode composition 1 as shown in FIG. did. The obtained electrode composition 1 was dried at 120 ° C. under a reduced pressure atmosphere for 16 hours or more, and then the mass, sheet thickness and dimensions were measured and used for the following measurements.
　図２に示すように、宝泉（株）製のエッチングアルミニウム箔３に日立化成工業（株）製の導電性接着剤２「ＨＩＴＡＳＯＬ　ＧＡ－７１５」を塗布厚みが１００μｍになるように塗布した。そして、図３に示すように、導電性接着剤２が塗布されたエッチングアルミニウム箔３と、先にカットしておいたシート状の電極組成物１とを接着した。そして、宝泉（株）製のアルミニウム製のシーラント５付きタブ４をエッチングアルミニウム箔３に超音波溶接機を用いて溶接した。溶接後、１２０℃で真空乾燥し、アルミニウム製の集電体を備える分極性電極６を得た。 As shown in FIG. 2, the etched aluminum foil 3 manufactured by Hosen Co., Ltd. was coated with the conductive adhesive 2 "HITASOL GA-715" manufactured by Hitachi Kasei Kogyo Co., Ltd. so that the coating thickness was 100 μm. Then, as shown in FIG. 3, the etched aluminum foil 3 coated with the conductive adhesive 2 and the sheet-shaped electrode composition 1 previously cut were adhered to each other. Then, a tab 4 with an aluminum sealant 5 manufactured by Hosen Co., Ltd. was welded to the etched aluminum foil 3 using an ultrasonic welding machine. After welding, it was vacuum dried at 120 ° C. to obtain a polar electrode 6 provided with an aluminum current collector.
　図４に示すように、宝泉（株）製のアルミニウム積層樹脂シートを長方形（縦２００ｍｍ×横６０ｍｍ）に切り出し２つ折にして、１辺（図４中の（１））を熱圧着して残る２辺が開放された袋状外装シート７を準備した。日本高度紙工業（株）製のセルロース製セパレータ「ＴＦ－４０」（図示せず）を介して上記の分極性電極６を２枚重ね合わせた積層体を作製した。この積層体を外装シート７に挿入して、タブ４が接する１辺（図５中の（２））を熱圧着して分極性電極６を固定した。そして、１２０℃、減圧雰囲気下で１６時間以上真空乾燥させた後、アルゴン雰囲気（露点－９０℃以下）のドライボックス内で電解液を注入した。電解液としては、キシダ科学（株）製の１．０ｍｏｌ／Ｌのテトラエチルアンモニウム・テトラフルオロボレートのアセトニトリル溶液を使用した。外装シート７内で積層体に電解液を含侵させた後、外装シート７の残る１辺（図５中の（３））を熱圧着して図５に示す電気化学デバイス８を作製した。 As shown in FIG. 4, an aluminum laminated resin sheet manufactured by Hosen Co., Ltd. is cut into a rectangle (length 200 mm × width 60 mm), folded in half, and one side ((1) in FIG. 4) is thermocompression bonded. A bag-shaped exterior sheet 7 having the remaining two sides open was prepared. A laminated body in which two of the above polar electrodes 6 were laminated was produced via a cellulose separator "TF-40" (not shown) manufactured by Nippon Kodoshi Paper Industry Co., Ltd. This laminated body was inserted into the exterior sheet 7, and one side ((2) in FIG. 5) in contact with the tab 4 was thermocompression bonded to fix the polar electrode 6. Then, after vacuum-drying at 120 ° C. under a reduced pressure atmosphere for 16 hours or more, the electrolytic solution was injected in a dry box with an argon atmosphere (dew point −90 ° C. or lower). As the electrolytic solution, an acetonitrile solution of 1.0 mol / L tetraethylammonium tetrafluoroborate manufactured by Kishida Scientific Co., Ltd. was used. After impregnating the laminate with the electrolytic solution in the exterior sheet 7, the remaining one side ((3) in FIG. 5) of the exterior sheet 7 was thermocompression bonded to prepare the electrochemical device 8 shown in FIG.
［静電容量測定］
　得られた電気化学デバイス８を菊水電子工業（株）製の「ＣＡＰＡＣＩＴＯＲ　ＴＥＳＴＥＲ　ＰＦＸ２４１１」を用いて、２５℃および－３０℃において、到達電圧３．０Ｖまで、電極表面積あたり５０ｍＡで定電流充電し、さらに、３．０Ｖで２５分、定電圧下補充電し、補充電完了後、２５ｍＡで放電した。得られた放電曲線データをエネルギー換算法で算出し静電容量（Ｆ）とした。具体的には、充電の後電圧がゼロになるまで放電し、このとき放電した放電エネルギーから静電容量（Ｆ）を計算した。そして、電極の炭素質材料質量で割った静電容量（Ｆ／ｇ）を求めた。 [Capacitance measurement]
The obtained electrochemical device 8 was charged at 25 ° C. and -30 ° C. using "CAPACITOR TESTER PFX2411" manufactured by Kikusui Electronics Co., Ltd. at a constant current of 50 mA per electrode surface surface up to a maximum voltage of 3.0 V. Further, the supplementary charge was performed at 3.0 V for 25 minutes under a constant voltage, and after the supplementary charge was completed, the battery was discharged at 25 mA. The obtained discharge curve data was calculated by the energy conversion method and used as the capacitance (F). Specifically, after charging, the battery was discharged until the voltage became zero, and the capacitance (F) was calculated from the discharged energy discharged at this time. Then, the capacitance (F / g) obtained by dividing by the mass of the carbonaceous material of the electrode was obtained.
［耐久性試験］
　耐久性試験は先に記述した静電容量測定後、６０℃の恒温槽中にて３．０Ｖの電圧を印加しながら６００時間保持した後で、上記と同様にして２５℃および－３０℃において静電容量測定を行った。耐久性試験前後の静電容量から、下記の式に従いそれぞれの温度についての容量維持率を求めた。６０℃の恒温槽中にて３．０Ｖの電圧印加開始前を耐久試験前とし、６００時間保持した後を耐久試験後とした。
　　容量維持率（％）
　　　＝耐久性試験後の炭素質材料質量あたりの静電容量
　　　　　　／耐久性試験前の炭素質材料質量あたりの静電容量×１００ [Durability test]
The durability test is performed at 25 ° C. and -30 ° C. in the same manner as above after holding for 600 hours while applying a voltage of 3.0 V in a constant temperature bath at 60 ° C. after measuring the capacitance described above. Capacitance measurement was performed. From the capacitance before and after the durability test, the capacitance retention rate at each temperature was calculated according to the following formula. Before the start of application of a voltage of 3.0 V in a constant temperature bath at 60 ° C. was defined as before the durability test, and after holding for 600 hours was defined as after the durability test.
Capacity retention rate (%)
= Capacitance per carbon material mass after durability test / Capacitance per carbon material mass before durability test x 100
［ガス発生量の測定］
　発生したガス量は、測定電極セルの乾燥質量と水中の質量を測り、発生した浮力および水の密度からセル体積を求め、耐久性試験前後のセル体積の変化から算出したガス体積量を測定時の温度差で補正し、求めた。すなわち、ガス発生量は下記の式に従って求めた。なお、式中、セル質量Ａとは空気中でのセル質量（ｇ）を表し、セル質量Ｗとは水中でのセル質量（ｇ）を表す。
　ガス発生量（ｃｃ）＝
｛（耐久試験後のセル質量Ａ－耐久試験後のセル質量Ｗ）
　　　　－（耐久性試験前のセル質量Ａ－耐久性試験前のセル質量Ｗ）｝／
（２７３＋耐久性試験後の測定温度（℃）／（２７３＋耐久性試験前の測定温度（℃））
　上記のガス発生量をさらに電極組成物を構成する炭素質材料質量で割った値を、炭素質材料質量あたりのガス発生量（ｃｃ／ｇ）とした。 [Measurement of gas generation]
The amount of gas generated is measured by measuring the dry mass of the measurement electrode cell and the mass in water, determining the cell volume from the generated buoyancy and water density, and measuring the gas volume calculated from the change in cell volume before and after the durability test. It was corrected by the temperature difference of. That is, the amount of gas generated was calculated according to the following formula. In the formula, the cell mass A represents the cell mass (g) in air, and the cell mass W represents the cell mass (g) in water.
Gas generation amount (cc) =
{(Cell mass A after endurance test-Cell mass W after endurance test)
-(Cell mass A before durability test-Cell mass W before durability test)} /
(273 + measured temperature after durability test (° C) / (273 + measured temperature before durability test (° C)))
The value obtained by further dividing the above gas generation amount by the carbonaceous material mass constituting the electrode composition was defined as the gas generation amount (cc / g) per carbonic material mass.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に示すように、実施例１～３において、本発明の炭素質材料を用いた分極性電極（１）、（６）、（７）を用いて作製された電気化学デバイスは、比較例１～９の炭素質材料（２）～（５）、（８）～（１２）を用いてそれぞれ作製した電気化学デバイスと比較して、初期静電容量が高く、初期静電容量を維持しつつ、且つ、ガス発生量をも抑制されていることが示される。 As shown in Table 2, in Examples 1 to 3, the electrochemical devices produced by using the polarization electrodes (1), (6), and (7) using the carbonaceous material of the present invention are comparative examples. Compared with the electrochemical devices manufactured using the carbonaceous materials (2) to (5) and (8) to (12) of 1 to 9, the initial capacitance is higher and the initial capacitance is maintained. At the same time, it is shown that the amount of gas generated is also suppressed.
　本発明の電気化学デバイスは、比表面積や細孔容積の低下に伴う初期容量の低下を抑制し、耐久試験後においても十分な静電容量を保持でき、またガス発生量の抑制効果も高いことが示された。 The electrochemical device of the present invention suppresses a decrease in initial capacitance due to a decrease in specific surface area and pore volume, can maintain a sufficient capacitance even after a durability test, and has a high effect of suppressing gas generation. It has been shown.
　以上より、本発明の炭素質材料を電極に使用すると、初期静電容量が高く、ガス発生抑制効果が高く、優れた耐久性を有する電気化学デバイスを得ることができることが明らかである。 From the above, it is clear that when the carbonaceous material of the present invention is used for an electrode, an electrochemical device having a high initial capacitance, a high gas generation suppressing effect, and excellent durability can be obtained.
　１　　　電極組成物
　２　　　導電性接着剤
　３　　　エッチングアルミニウム箔
　４　　　タブ
　５　　　シーラント
　６　　　分極性電極
　７　　　袋状外装シート
　８　　　電気化学デバイス
　（１）　熱圧着された一辺
　（２）　タブが接する一辺
　（３）　袋状外装シートの残る一辺 1 Electrode composition 2 Conductive adhesive 3 Etched aluminum foil 4 Tabs 5 Sealant 6-minute polar electrode 7 Bag-shaped exterior sheet 8 Electrochemical device (1) Thermocompression-bonded side (2) One side where tabs touch (3) Bag-shaped The remaining side of the exterior sheet

Claims (9)

  1. 　ＢＥＴ比表面積が１５５０～２５００ｍ２／ｇであり、比表面積あたりの酸素含量／水素含量の値が１．００～２．１０ｍｇ／ｍ２であり、荷重１２ｋＮにおける粉体抵抗測定による導電率が１０～１５Ｓ／ｃｍである炭素質材料。 The BET specific surface area is 1550 to 2500 m 2 / g, the oxygen content / hydrogen content value per specific surface area is 1.00 to 2.10 mg / m 2 , and the conductivity measured by powder resistance measurement at a load of 12 kN is 10. A carbonaceous material of ~ 15 S / cm.
  2. 　酸素含量／水素含量の値が２．０～４．３である、請求項１に記載の炭素質材料。 The carbonaceous material according to claim 1, wherein the oxygen content / hydrogen content value is 2.0 to 4.3.
  3. 　炭素質材料が植物由来の炭素前駆体に基づく、請求項１または２に記載の炭素質材料。 The carbonaceous material according to claim 1 or 2, wherein the carbonaceous material is based on a plant-derived carbon precursor.
  4. 　炭素前駆体が椰子殻由来である、請求項１～３のいずれかに記載の炭素質材料。 The carbonaceous material according to any one of claims 1 to 3, wherein the carbon precursor is derived from coconut shell.
  5. 　炭素質材料前駆体を３３０℃以上に酸化性ガス雰囲気下で加熱する加熱工程と、酸化性ガス雰囲気下で３３０℃以上に加熱された炭素質材料前駆体を非酸化性ガス雰囲気下で降温する降温工程とを含み、
    　前記酸化性ガス雰囲気下で実施される加熱工程が１回含まれる場合には、前記加熱工程に続けて前記降温工程が実施され、
    　前記酸化性ガス雰囲気下で実施される加熱工程が複数回含まれる場合には、少なくとも最終の酸化性ガス雰囲気下で実施される加熱工程に続けて前記降温工程が実施され、
    　最終の酸化性ガス雰囲気下で実施される加熱工程に供される炭素質材料前駆体の荷重１２ｋＮにおける粉体抵抗測定による導電率が１１～１６Ｓ／ｃｍである、炭素質材料の製造方法。     A heating step in which the carbonaceous material precursor is heated to 330 ° C. or higher in an oxidizing gas atmosphere, and a carbonaceous material precursor heated to 330 ° C. or higher in an oxidizing gas atmosphere is cooled in a non-oxidizing gas atmosphere. Including the temperature lowering process
    When the heating step performed in the oxidizing gas atmosphere is included once, the temperature lowering step is carried out following the heating step.
    When the heating step performed in the oxidizing gas atmosphere is included a plurality of times, at least the heating step performed in the final oxidizing gas atmosphere is followed by the temperature lowering step.
    A method for producing a carbonaceous material, wherein the conductivity is 11 to 16 S / cm by measuring the powder resistance of the carbonaceous material precursor to be subjected to the heating step carried out in the final oxidizing gas atmosphere at a load of 12 kN.
  6. 　前記降温工程において、炭素質材料前駆体の温度を２００℃以下まで降温する、請求項５に記載の炭素質材料の製造方法。 The method for producing a carbonaceous material according to claim 5, wherein the temperature of the carbonaceous material precursor is lowered to 200 ° C. or lower in the temperature lowering step.
  7. 　請求項１～４のいずれかに記載の炭素質材料から形成される電気化学デバイス用電極活物質。 An electrode active material for an electrochemical device formed from the carbonaceous material according to any one of claims 1 to 4.
  8. 　請求項７に記載の電気化学デバイス用電極活物質含む電気化学デバイス用電極。 Electrode for an electrochemical device according to claim 7. Electrode for an electrochemical device containing an active material.
  9. 　請求項８に記載の電気化学デバイス用電極を備える電気化学デバイス。 An electrochemical device including the electrode for the electrochemical device according to claim 8.
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